CN219227455U

CN219227455U - Adjustable piezoelectric driving type sleeve unfolding and folding mechanism

Info

Publication number: CN219227455U
Application number: CN202222920257.1U
Authority: CN
Inventors: 韩强; 孙宝玉; 杨会生; 黄炜祺; 关英俊
Original assignee: Changchun University of Technology
Current assignee: Changchun University of Technology
Priority date: 2022-11-03
Filing date: 2022-11-03
Publication date: 2023-06-20
Anticipated expiration: 2032-11-03

Abstract

An adjustable piezoelectric driving sleeve unfolding and folding mechanism belongs to the technical field of space unfolding and folding mechanisms. The sleeve expanding and contracting mechanism aims at solving the problems of complex structure, lower resolution, large mass and the like of the conventional sleeve expanding and contracting mechanism. The utility model comprises a piezoelectric driver group, a driver bracket, a final stage sleeve and a primary sleeve; the piezoelectric driver group comprises three piezoelectric drivers, wherein each piezoelectric driver consists of a composite hinge, a piezoelectric stack, a gasket, a machine meter screw and a positioning screw; each piezoelectric driver is fixed on the driver bracket through a positioning screw after being adjusted through an adjusting screw; the driving foot is tightly contacted with the outer surface of the barrel 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 cylinder cores of the two cylinders are of hollow triangular prism structures, so that the contact area between the driving foot and the driving foot can be increased, the rotational freedom degree of the two sleeves can be limited, and a guiding effect can be provided for the movement of the sleeves. The utility model is used for manufacturing the sleeve unfolding and folding mechanism.

Description

Adjustable piezoelectric driving type sleeve unfolding and folding mechanism

Technical Field

The utility model relates to an adjustable piezoelectric driving type sleeve expanding and contracting mechanism, and belongs to the technical field of space expanding and contracting mechanisms.

Background

Space expansion and contraction mechanisms are one of the most commonly used mechanisms in the aerospace and engineering machinery fields. The device has the advantages of simple structure, clear principle and less influence by temperature, thereby being widely applied. There are many kinds of folding and unfolding mechanisms, including hinged trusses, winding, inflatable, thin-walled tubes, etc., of which sleeve space folding and unfolding mechanisms are the most commonly used. It is moved by the secondary sleeve relative to the axis of the final sleeve to effect the deployment action. At present, a complex system consisting of a screw nut component, a rope pulley block, an electromagnetic motor and other basic components is generally adopted by a sleeve unfolding and folding mechanism so as to achieve the aim of unfolding and folding, and the problems of complex structure, weight, energy loss and the like generally exist in the structures.

Disclosure of Invention

The utility model provides an adjustable piezoelectric driving type sleeve expanding and contracting mechanism, which aims to solve the problems of large mass, complex structure and the like of the existing space expanding and contracting mechanism.

The utility model relates to an adjustable piezoelectric driving type sleeve expanding and contracting mechanism which mainly comprises a piezoelectric driver, a bracket, a primary sleeve and a final sleeve.

The piezoelectric driver comprises two piezoelectric stacks, two gaskets, two machine screws, two positioning screws and a compound hinge.

The piezoelectric driving assembly comprises three drivers, each driver is uniformly assembled on the bracket at 120 degrees, and driving feet on the drivers simultaneously drive the final stage sleeve.

The two piezoelectric stacks are respectively assembled into two transverse and longitudinal piezoelectric stack grooves of the composite hinge and then are pre-tightly assembled by using gaskets and machine screws.

The combined bracket is assembled above the primary sleeve through an assembly screw, the barrel core of the primary sleeve is matched with the barrel core of the final sleeve, and at the moment, three driving feet are tightly contacted with the outer surface of the barrel core of the primary sleeve; because the two sleeve cylinder cores are hollow triangular prisms, the rotary freedom degree and the guiding function between the two sleeves can be limited when the sleeves work.

The two piezo stacks on the same driver are stacked in a T-shaped assembly.

The three transverse piezoelectric stacks of the piezoelectric driving assembly are on the same plane, and the three longitudinal piezoelectric stacks are on the same plane.

The utility model has the beneficial effects that the driving unit is structurally arranged in the sleeve, so that the whole space utilization rate of the mechanism is greatly improved; the power source of the mechanism adopts piezoelectric ceramics, and has the advantages that: no mechanical friction, no clearance, high motion sensitivity, low energy consumption, small volume, light weight, high response speed, high power and the like, and the folding precision of the spatial sleeve folding mechanism is ensured to a great extent; the driving unit has the advantages of simplicity, microminiaturization and the like, effectively reduces the overall quality of the mechanism, and greatly solves the problem of insufficient load of the carrier; because the driving mode is the stick-slip driving, lubrication is not needed to be considered, the device is more suitable for the space working environment, and the adjustment of the friction force can be realized by adjusting the time sequence of the voltages at the two ends of the transverse piezoelectric stack; and the number of drivers may be increased according to the basic shape of the sleeve barrel core to meet the larger output force.

Drawings

FIG. 1 is a cross-sectional view of an adjustable piezoelectric driven sleeve deployment and deployment mechanism according to the present utility model;

FIG. 2 is a three-dimensional exploded view of an adjustable piezoelectric driven sleeve deployment and deployment mechanism according to the present utility model;

FIG. 3 is a three-dimensional exploded view of the piezoelectric actuator of FIG. 2;

FIG. 4 is an assembled schematic view of the piezoelectric actuator of FIG. 2;

FIG. 5 is an assembled cross-sectional view of the primary sleeve and the final sleeve;

FIG. 6 is a timing diagram of control signals for a piezo stack during deployment according to an embodiment;

fig. 7 is a timing diagram of control signals for a piezoelectric stack during shrinkage according to an embodiment.

Detailed Description

Referring to fig. 2, 3, 4, 5, 6, and 7, the adjustable piezoelectric driving type sleeve expanding and contracting mechanism according to the present embodiment includes a piezoelectric driver (1), a bracket (2), a final stage sleeve (3), and a primary stage sleeve (4).

The piezoelectric driver (1) comprises a transverse piezoelectric stack (1-1), a transverse gasket (1-2), a transverse machine screw (1-3), a longitudinal piezoelectric stack (1-4), a longitudinal gasket (1-5), a longitudinal machine screw (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 the transverse gasket (1-2) and the transverse machine screw (1-3); the longitudinal piezoelectric stack (1-4) is assembled in a longitudinal piezoelectric stack groove of the composite hinge (1-8) through the longitudinal gasket (1-5) and the longitudinal machine screw (1-6).

The piezoelectric drivers (1) are uniformly distributed on the bracket (2) at 120 degrees, and each piezoelectric driver is assembled on the bracket through the positioning screw (5) and the adjusting screw (7).

The combined bracket (2) is assembled above the primary sleeve (4) through an assembling screw (6), the cylinder core of the primary sleeve (4) is matched with the cylinder core of the final sleeve (3), and at the moment, the three driving feet (1-8-1) are tightly contacted with the outer surface of the cylinder core of the final sleeve (3); because the two sleeve cylinder cores are hollow triangular prisms, the rotary freedom degree and the guiding function between the two sleeves can be limited when the sleeves work.

The piezoelectric driver (1) in the embodiment adopts a stick-slip driving principle, and the driving foot (1-8-1) is tightly contacted with the outer surface of the cylinder core of the final-stage sleeve (3).

The driving principle of the piezoelectric driver (1) is that the inverse piezoelectric effect of piezoelectric ceramics is used as a power source of the driver, voltage is applied to two ends of the piezoelectric ceramics, mechanical stress is generated, and the mutual conversion between mechanical energy and electric energy is realized; the driving principle of the piezoelectric stick-slip driving is that the piezoelectric ceramics are rapidly deformed to generate acceleration, namely inertia impact, so that the dynamic friction force cannot provide the acceleration of a moving object, thereby keeping the moving object at an original position, and then the piezoelectric ceramics are controlled to return at a small speed, thereby realizing that the static friction force drives the object to move so as to realize micro displacement; the piezoelectric stick-slip drive has the advantages of high response speed, no electromagnetic interference, simple structure and the like.

When the adjustable piezoelectric driving type sleeve folding and unfolding mechanism is in a working state, six piezoelectric stacks in the three groups of piezoelectric drivers (1) receive driving signals, and the driving feet (1-8-1) are controlled to transversely and longitudinally displace and output frequency by controlling the voltage and the frequency at two ends of the piezoelectric stacks.

Working sequence when the sleeve is unfolded: at 0-t ₁ The phased piezoelectric stack is driven via an electrical signal to slowly elongate along the x-axis, while the foot is driven to move along the x-axis. At 0-t ₁ The stage transverse piezo-electric stack is driven via an electrical signal to slowly elongate along the y-axis, at which time the drive foot increases positive pressure with the final sleeve barrel in the y-axis direction, resulting in an increase in friction between the final sleeve barrel and the drive foot. At the same time the sleeve is unfolded a distance. At t ₁ -t ₂ The phased piezoelectric stack is driven via an electrical signal to slowly contract along the x-axis, which drives the foot to move along the x-axis. At t ₁ -t ₂ The stage transverse piezoelectric stack is driven by an electric signal to slowly shrink along the y axis, at the moment, the positive pressure between the driving foot and the barrel center of the final-stage sleeve is reduced in the y axis direction, so that the friction force between the barrel center of the final-stage sleeve and the driving foot is reduced, during the rapid shrinkage process, the static friction between the driving foot and the barrel center of the final-stage sleeve is changed into sliding friction, the driving foot returns to the initial position, the final-stage sleeve moves forwards for one step distance, and the expansion of the sleeve mechanism is completed by repeating the process for a plurality of times.

Working sequence when the sleeve is contracted: at 0-t ₃ The phased piezoelectric stack is driven via an electrical signal to rapidly elongate along the x-axis, which drives the foot to move along the x-axis. At 0-t ₃ The stage transverse piezo-electric stack is driven via an electrical signal to rapidly elongate along the y-axis, at which time the drive foot increases positive pressure with the final stage sleeve barrel in the y-axis direction, resulting in an increase in friction between the final stage sleeve barrel and the drive foot. Due to the inertia of the final stage sleeve,while the sleeve is substantially stationary. At t ₃ -t ₄ The phased piezoelectric stack is driven via an electrical signal to slowly contract along the x-axis, which drives the foot to move along the x-axis. At t ₃ -t ₄ The stage transverse piezoelectric stack is driven by an electric signal to slowly shrink along the y axis, at the moment, the positive pressure between the drive foot and the cylinder core of the final sleeve is reduced in the y axis direction, and in the slow shrinkage process, the final sleeve moves backwards by one step distance due to the fact that the friction force is static friction force, and the shrinkage of the sleeve mechanism is completed through repeating the process for a plurality of times.

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

In the piezoelectric driver (1) in the embodiment, the included angle between two adjacent drivers is 120 degrees, and the three driving feet (1-8-1) are guaranteed to be on the same plane, and the plane is parallel to the end face of the sleeve, so that the stress of each end face of each sleeve cylinder (the cylinder is triangular prism) is equal.

Claims

1. An adjustable piezoelectric driving type sleeve folding and unfolding mechanism is characterized by comprising a piezoelectric driver (1), a bracket (2), a final sleeve (3) and a primary sleeve (4); the final sleeve (3) is assembled on the primary sleeve (4), the barrel centers of the final sleeve (3) and the primary sleeve (4) are hollow triangular prisms, the rotational freedom between the two sleeves is limited, and a guiding effect is provided for sleeve unfolding and folding.

2. The adjustable piezoelectric driving type sleeve expanding and contracting mechanism according to claim 1, wherein the piezoelectric driver (1) comprises a transverse piezoelectric stack (1-1), a transverse gasket (1-2), a transverse machine screw (1-3), a longitudinal piezoelectric stack (1-4), a longitudinal gasket (1-5), a longitudinal machine screw (1-6), a positioning screw head (1-7) and a compound hinge (1-8); the transverse piezoelectric stack (1-1) is assembled in a transverse piezoelectric stack groove of the composite hinge (1-8) through the transverse gasket (1-2) and the transverse machine screw (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 the normal working state, the voltage at two ends of the two groups of piezoelectric stacks is increased, so that the longitudinally arranged piezoelectric stacks (1-4) longitudinally extend to drive the driving feet (1-8-1) on the composite hinge (1-8) to longitudinally move; the transverse piezoelectric stack (1-1) is transversely stretched to drive the driving foot (1-8-1) on the composite hinge (1-8) to move transversely; the friction force is increased by increasing the positive pressure between the driving foot (1-8-1) and the cylinder center of the final sleeve (3), so as to drive the final sleeve (3) to move longitudinally; the expanding and contracting functions are realized by changing the time sequence of voltages at 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 voltages at two ends of the transverse piezoelectric stack (1-1).

3. An adjustable piezoelectric driven type sleeve folding and unfolding mechanism as claimed in claim 2 and characterized in that each piezoelectric driver (1) is assembled on a support (2) through a positioning screw (5), the support (2) is assembled on a primary sleeve (4) through an assembling screw (6), and driving feet (1-8-1) on the compound hinges (1-8) are tightly contacted with the barrel center of a final sleeve (3).

4. An adjustable piezoelectric driving type sleeve folding and unfolding mechanism as claimed in claim 1 or 2 and characterized in that each piezoelectric driver (1) is uniformly distributed on a bracket at an angle of 120 degrees coaxially, each driving foot (1-8-1) is perpendicular to each plane of a triangular prism of a barrel core of a final stage sleeve (3), and the number of drivers can be increased according to the basic shape of the barrel core of the sleeve so as to meet larger output force.