CN115566929A - An Adjustable Piezoelectric-Driven Sleeve Expanding and Retracting Mechanism - Google Patents

Abstract

The utility model provides an adjustable piezoelectricity drive type sleeve exhibition receipts mechanism, belongs to space exhibition receipts mechanism technical field. The sleeve unfolding and folding mechanism aims at solving the problems of complex structure, high energy consumption, low unfolding and folding resolution, large mechanism mass and the like of the conventional sleeve unfolding and folding mechanism. The invention comprises a piezoelectric driver group, a driver bracket, a final stage sleeve, a primary sleeve, a positioning screw, an assembling screw and an adjusting screw; the piezoelectric driver group comprises three independent piezoelectric drivers, and each piezoelectric driver consists of a composite hinge, a piezoelectric stack, a gasket, a bolt and a positioning screw; each piezoelectric driver is adjusted by an adjusting screw and then fixed on a driver bracket by a positioning screw, so that the tail end face of the driving foot is in close contact with the outer surface of the cylinder core of the final stage sleeve; the adjusting screw is assembled on the driver bracket and used for adjusting the position of the driver; the barrel centers of the two barrels are of hollow triangular prism structures, so that the contact area between a driving foot and the driving foot can be increased, the rotational freedom of the two sleeves can be limited, and a guiding effect can be provided for the movement of the sleeves. The sleeve unfolding and folding mechanism is used for manufacturing the sleeve unfolding and folding mechanism.

Description

An Adjustable Piezoelectric Driven Sleeve Expanding and Retracting Mechanism

technical field

The invention relates to an adjustable piezoelectric-driven sleeve expansion and retraction mechanism, which belongs to the technical field of space expansion and retraction mechanisms.

technical background

The space retractable mechanism is one of the most commonly used mechanisms in the field of aerospace and construction machinery. It is simple in structure, clear in principle and less affected by temperature, so it has been widely used; Collectors are the most commonly used one. It moves the secondary sleeve relative to the axis of the last sleeve to realize the unfolding action; at present, the sleeve expansion and retraction mechanism generally adopts a complex system composed of screw nut assembly, rope pulley block, electromagnetic motor and other basic components to achieve the purpose of expansion and retraction , and these structures generally have problems such as relatively complicated structure, weight, and energy loss.

The purpose of the present invention is to solve the problems of large mass and complicated structure of the existing space expansion and retraction mechanism, and provide an adjustable piezoelectric-driven sleeve expansion and retraction mechanism.

The present invention is an adjustable piezoelectric-driven sleeve extension and retraction mechanism, and its main structure includes a piezoelectric driver, a bracket, a primary sleeve, and a final sleeve.

The piezoelectric actuator consists of two piezoelectric stacks, two spacers, two machine screws, two set screws, and a composite hinge.

The piezoelectric drive assembly includes three drivers, each driver is uniformly assembled on the bracket at an angle of 120°, and the driving foot on the driver drives the final sleeve at the same time.

The two piezoelectric stacks are respectively installed into the two horizontal and vertical piezoelectric stack slots of the composite hinge, and then preloaded with gaskets and machine screws for assembly.

The combined bracket is assembled above the primary sleeve through assembly screws, and the core of the primary sleeve and the core of the final sleeve cooperate with each other. At this time, the three driving feet are in close contact with the outer surface of the core of the primary sleeve; because the two sleeves The cylinder centers are all hollow triangular prisms, so when the sleeves are working, they can play the role of restricting the degree of freedom of rotation and guiding between the two sleeves.

The two piezoelectric stacks on the same driver are assembled in a T shape.

The piezoelectric drive assembly has three horizontal piezoelectric stacks on the same plane, and three vertical piezoelectric stacks on the same plane.

The beneficial effect of the present invention is that the driving unit is structurally arranged inside the sleeve, so that the overall space utilization rate of the mechanism is greatly improved; the power source of the mechanism adopts piezoelectric ceramics, which has the following advantages: no mechanical friction, no gap, no movement High sensitivity, low energy consumption, small size, light weight, fast response, large power, etc., to a great extent ensure the retracting accuracy of the space sleeve retracting mechanism; the drive unit has the advantages of simplification and miniaturization, effectively reducing the The overall quality of the mechanism is improved, and the phenomenon of insufficient load of the carrier is solved to a great extent; because the drive mode is stick-slip drive, there is no need to consider lubrication, which is more suitable for the space working environment, and the voltage at both ends of the transverse piezoelectric stack can also be adjusted The timing can realize the adjustment of the friction force; and the number of drivers can be increased according to the basic shape of the sleeve core to meet greater output force.

Description of drawings

Fig. 1 is a sectional view of an adjustable piezoelectric-driven sleeve expansion and retraction mechanism according to the present invention;

Fig. 2 is a three-dimensional exploded view of an adjustable piezoelectric-driven sleeve expansion and retraction mechanism according to the present invention;

Fig. 3 is a three-dimensional exploded view of the piezoelectric driver in Fig. 2;

Fig. 4 is a schematic diagram of the assembly of the piezoelectric driver in Fig. 2;

Fig. 5 is an assembly sectional view of the primary sleeve and the final sleeve;

Fig. 6 is a timing diagram of control signals of the piezoelectric stack during deployment described in the specific embodiment;

Fig. 7 is a timing diagram of control signals of the piezoelectric stack during contraction according to the specific embodiment.

specific implementation plan

2, 3, 4, 5, 6, and 7 are used to illustrate this embodiment. An adjustable piezoelectric-driven sleeve expansion mechanism described in this embodiment includes a piezoelectric driver (1), a bracket (2) Primary sleeve (3), primary sleeve (4).

The piezoelectric driver (1) includes a horizontal piezoelectric stack (1-1), a horizontal gasket (1-2), a horizontal machine screw (1-3), a vertical piezoelectric stack ( 1-4), vertical spacers (1-5), vertical machine screws (1-6), positioning screw heads (1-7), compound hinges (1-8).

The horizontal piezoelectric stack (1-1) is assembled in the horizontal piezoelectric stack groove of the composite hinge (1-8) through the horizontal spacer (1-2) and the horizontal machine screw (1-3); The vertical piezoelectric stack (1-4) is assembled in the vertical piezoelectric stack groove of the compound hinge (1-8) through the vertical spacer (1-5) and the vertical machine screw (1-6).

The piezoelectric drivers (1) are evenly distributed on the bracket (2) at an angle of 120°, and each piezoelectric driver is assembled on the bracket through a positioning screw (5) and an adjusting screw (7).

The assembled bracket (2) is assembled above the primary sleeve (4) through the assembly screw (6), and the core of the primary sleeve (4) and the core of the final sleeve (3) cooperate with each other. (1-8-1) is in close contact with the outer surface of the core of the final sleeve (3); since the cores of the two sleeves are hollow triangular prisms, the freedom of rotation between the two sleeves can be restricted when the sleeves are working degree and orientation.

The piezoelectric driver (1) in this embodiment adopts the stick-slip driving principle, and the driving foot (1-8-1) is in close contact with the outer surface of the core of the final sleeve (3).

The driving principle of piezoelectric actuator (1) is to use the inverse piezoelectric effect of piezoelectric ceramics as the power source of the actuator, apply voltage to both ends of piezoelectric ceramics to generate mechanical stress, and realize the mutual conversion between mechanical energy and electrical energy; The driving principle of electrostick-slip driving is that the rapid deformation of piezoelectric ceramics produces acceleration, that is, inertial impact, so that dynamic friction cannot provide the acceleration of the moving object, so as to maintain the original position, and then control the piezoelectric ceramics to return at a smaller speed, so as to achieve Static friction drives the object to move to achieve micro-displacement; piezoelectric stick-slip drive has the advantages of fast response, no electromagnetic interference, and simple structure.

When the adjustable piezoelectric-driven sleeve retractable mechanism of this embodiment is in working state, the six piezoelectric stacks in the three sets of piezoelectric drivers (1) receive the drive signals, and control the voltage at both ends of the piezoelectric stack Voltage and frequency control the displacement and output frequency of the drive foot (1-8-1) in the horizontal and vertical directions.

The working sequence when the sleeve is unfolded: in the 0-t ₁ stage, the vertical piezoelectric stack is slowly elongated along the x-axis through the electric signal drive, and at this time the driving foot moves along the x-axis; in the 0-t ₁ stage, the horizontal piezoelectric stack passes through The electric signal drive slowly elongates along the y-axis. At this time, the positive pressure between the driving foot and the center of the last-stage sleeve increases in the direction of the y-axis, resulting in an increase in the friction between the center of the final-stage sleeve and the driving foot. At the same time, the sleeve is expanded for a certain distance; in the t ₁ -t ₂ stage, the vertical piezoelectric stack is driven by an electric signal to slowly shrink along the x-axis, and at this time the driving foot moves along the x-axis; in the t ₁ -t ₂ stage, the horizontal piezoelectric stack The electrical stack is driven by electrical signals to slowly shrink along the y-axis. At this time, the driving foot reduces the positive pressure on the center of the last-stage sleeve in the direction of the y-axis, resulting in a decrease in the friction between the center of the final-stage sleeve and the driving foot. Small, in the process of rapid contraction, due to the inertia of the final sleeve and the reduced friction, at this time, the static friction between the driving foot and the center of the final sleeve will become sliding friction, and the driving foot will return to the initial state position, while the final sleeve moves forward by one step, and the expansion of the sleeve mechanism is completed by repeating the above process several times.

The working sequence when the sleeve shrinks: in the 0-t ₃ stage, the vertical piezoelectric stack is driven by an electric signal to quickly elongate along the x-axis, and at this time the driving foot moves along the x-axis; in the 0-t ₃ stage, the horizontal piezoelectric stack passes through The electrical signal is driven to elongate rapidly along the y-axis. At this time, the positive pressure between the driving foot and the center of the last-stage sleeve increases in the direction of the y-axis, resulting in an increase in the friction between the center of the final-stage sleeve and the driving foot; Due to the inertia of the final sleeve, the sleeve does not move substantially at the same time. In the t ₃ -t ₄ stage, the vertical piezoelectric stack is driven by an electric signal to slowly shrink along the x-axis, and the driving foot moves along the x-axis at this time; in the t ₃ -t ₄ stage, the horizontal piezoelectric stack is driven by an electric signal to slowly move along the y axis The shaft shrinks, at this time, the driving foot reduces the positive pressure on the center of the final sleeve in the direction of the y-axis. During the slow contraction process, since the friction force is static friction at this time, the final sleeve moves backward by one step , by repeating the above process several times, the shrinking of the sleeve mechanism is completed.

The expansion and contraction of the sleeve can be realized through the above process.

The included angle between two adjacent piezoelectric drivers (1) in this embodiment is 120°, and the three driving feet (1-8-1) are guaranteed to be on the same plane, which is parallel to the end surface of the sleeve. The force on each end face of each sleeve core (the core is a triangular prism) can be equal.

Claims (5)

1. The utility model provides an adjustable piezoelectricity drive type sleeve exhibition receipts mechanism which characterized in that exhibition receipts mechanism includes piezoelectric actuator (1), driver support (2), last stage sleeve (3), elementary sleeve (4).

2. The adjustable piezoelectric driving type sleeve expanding and contracting mechanism according to claim 1, wherein the final stage sleeve (3) is assembled on the primary stage sleeve (4), and the barrel centers of the final stage sleeve (3) and the primary stage sleeve (4) are triangular structures, so that the degree of freedom of rotation between the two sleeves is limited, and a guiding effect is provided for the expansion and contraction of the sleeve.

3. The piezoelectric driver (1) according to claim 1 comprises a transverse piezoelectric stack (1-1), a transverse gasket (1-2), a transverse bolt (1-3), a longitudinal piezoelectric stack (1-4), a longitudinal gasket (1-5), a longitudinal bolt (1-6), a positioning screw head (1-7) and a composite hinge (1-8); the transverse piezoelectric stack (1-1) is assembled in a transverse piezoelectric stack groove of the composite hinge (1-8) through a transverse gasket (1-2) and a transverse bolt (1-3); the longitudinal piezoelectric stack (1-4) is assembled in a longitudinal piezoelectric stack groove of the composite hinge (1-8) through a longitudinal gasket (1-5) and a longitudinal machine screw (1-6); under a normal working state, the voltages at two ends of the two groups of piezoelectric stacks are increased, so that the longitudinal piezoelectric stacks (1-4) longitudinally extend to drive the driving feet (1-8-1) on the composite hinges (1-8) to move longitudinally; transversely extending the transverse piezoelectric stack (1-1) to drive the driving foot (1-8-1) on the composite hinge (1-8) to move along the transverse direction; the friction force is increased by increasing the positive pressure of the driving feet (1-8-1) and the cylinder core of the last-stage sleeve (3), so that the last-stage sleeve (3) is driven to move longitudinally; the expansion and contraction functions are realized by changing the time sequence of the voltages at the two ends of the two groups of piezoelectric stacks; the adjustment of the friction force can be realized by adjusting the time sequence of the voltage at the two ends of the transverse piezoelectric stack (1-1).

4. An adjustable piezo-electric drive type sleeve deployment and retraction mechanism according to claim 3, wherein each piezo-electric actuator (1) is mounted on the bracket (2) by means of a set screw (5), the bracket (2) is mounted on the primary sleeve (4) by means of a mounting screw (6), and the driving feet (1-8-1) on the compound hinges (1-8) are in close contact with the barrel center of the final sleeve (3).

5. An adjustable piezo-driven telescopic mechanism according to claims 1 and 3, characterized in that each driver (1) is evenly distributed on the support at 120 ° with the same axis, and each driving foot (1-8-1) is perpendicular to each plane of the triangular prism of the last stage sleeve (3) cylinder center, and the number of drivers can be increased to meet larger output force according to the basic shape of the sleeve cylinder center.

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