CN201250820Y - Piezoelectric hydraulic linear motor - Google Patents

Abstract

The utility model relates to a piezoelectric hydraulic linear motor, which belongs to the field of electromechanical-hydraulic integration. The inlet of the piezoelectric pump is connected to the accumulator through a pipeline, and the accumulator is also connected to a reversing valve through a pipeline, and the reversing valve is connected to the outlet of the piezoelectric pump through a pipeline, and the reversing valve is also connected to the hydraulic pressure Cylinder cavity connection. The advantages are: the structure is novel, the fluid medium is used to transmit power, and the micro-amplitude reciprocating vibration of the piezoelectric ceramic can be effectively converted into the macroscopic linear motion of the hydraulic cylinder piston to obtain a large driving force and motion stroke, and can be accumulated one at a time. The method of liquid droplets realizes precise driving and control; at the same time, the structure and control of the piezoelectric hydraulic motor are simple, small in size and good in sealing, and can be used as a marking component.

Description

Piezoelectric hydraulic linear motor

technical field

The utility model belongs to the field of mechanical-electrical-hydraulic integration, and in particular relates to a piezoelectric hydraulic driver which utilizes a piezoelectric pump to drive liquid circulation and converts the high-frequency and small reciprocating vibrations of piezoelectric ceramics into regular macroscopic linear motion of hydraulic cylinder pistons. Electro-hydraulic linear motor.

Background technique

Piezoelectric ceramics have the characteristics of simple structure, fast response, no electromagnetic interference, low energy consumption, and easy control. They are widely used in aerospace, machinery, optical engineering, biomedicine, and fluid drive and control. At present, there are many forms of piezoelectric actuators that use piezoelectric ceramics as power components to achieve force and linear displacement output/control, which can be simply classified into three categories: 1) piezoelectric actuators that directly use piezoelectric body expansion and deformation to output force or displacement; 2) Piezoelectric actuators using amplification mechanisms such as levers and flexible hinges; 3) Stepping piezoelectric motors formed by clamping mechanisms or ultrasonic principles. The first two types of piezoelectric actuators have a simple structure and large output force, but the displacement is small, and the practical application is limited to a certain extent; the latter can obtain a large motion stroke, but the structure and control are complex and require high machining accuracy of the parts. Relying on friction to transmit force and displacement, the feed stiffness is low, and the output driving force is far lower than the pressure generated by the deformation of the piezoelectric body. It is only a few to tens of Newtons, which cannot meet the application occasions where the force and displacement are large. A new driver with small size, light weight, high output force, large displacement, fast speed and high energy efficiency is urgently needed in many fields. For example, application objects such as material testing machine, rocket engine thrust measurement test bench, micro-oscillation of helicopter rotor and active control of traditional aircraft surface usually require the driver to have a large output force and displacement to meet the requirements of structural control. The control object is mainly the load, which is loaded or unloaded through real-time large-scale precision displacement (two-way adjustment of thousands of newtons within a stroke range of several millimeters/centimeters), which is difficult for existing piezoelectric actuators to meet.

Contents of the invention

The utility model provides a piezoelectric hydraulic linear motor to solve the problem that the output force and displacement of the piezoelectric driver are small and cannot meet the actual needs. The technical scheme adopted by the utility model is: the inlet of the piezoelectric pump is connected to the accumulator through a pipeline, and the accumulator is also connected to a reversing valve through a pipeline, and the reversing valve and the outlet of the piezoelectric pump are connected through a pipeline Connected, the reversing valve is also connected with the cavity of the hydraulic cylinder through the pipeline.

One embodiment of the utility model is: the reversing valve adopts a 3-position 4-way valve.

One embodiment of the utility model is: the piezoelectric pump adopts a piezoelectric stack pump, and the piezoelectric stack pump is composed of a pump body, 1 to 10 piezoelectric stack vibrators, a rigid top block, an elastic diaphragm and a stop valve. , the pump body and the elastic diaphragm together form a pump chamber.

One embodiment of the present utility model is: the piezoelectric pump adopts a piezoelectric wafer pump, and the piezoelectric wafer pump is composed of a pump body, 1 to 10 piezoelectric wafer vibrators and a stop valve, and the pump body and piezoelectric wafer vibrators Together they form the pump cavity.

The medium-voltage electric pump of the utility model is a power element, which realizes the circulation and driving of the fluid; the function of the reversing valve is to control the flow of the fluid and the movement direction of the hydraulic cylinder piston; the function of the accumulator is to absorb the high-pressure fluid and supplement the low-pressure fluid, Store the difference in liquid volume caused by the unequal areas at both ends of the piston; the function of the hydraulic cylinder is to realize the output of force or displacement. The utility model is characterized in that it can obtain larger output force and motion stroke at the same time.

The utility model utilizes a piezoelectric pump to drive liquid circulation, realizes motion conversion and power transmission through the fluid medium, and then converts the high-frequency micro-amplitude reciprocating vibration of the piezoelectric vibrator into the linear motion of the piston of the hydraulic cylinder.

In one embodiment of the present utility model, it includes at least one piezoelectric pump, a reversing valve, an accumulator, a hydraulic cylinder, connecting pipelines and other parts. When the piezoelectric vibrator in the piezoelectric pump is deformed under the action of alternating voltage, the volume of the piezoelectric pump chamber and the fluid pressure will change, thereby pushing the opening and closing of the one-way valve: when the deformation of the piezoelectric vibrator When the volume of the piezoelectric pump chamber decreases and the fluid pressure increases, the inlet valve of the piezoelectric pump is closed and the outlet valve is opened, and the high-pressure fluid in the pump chamber enters a cavity of the hydraulic cylinder through the reversing valve; at the same time, the hydraulic cylinder The liquid in one cavity enters the accumulator, and the piston of the hydraulic cylinder moves one step; after the alternating voltage is reversed, the volume of the pump cavity of the piezoelectric pump increases, and the pressure of the liquid in the pump cavity decreases, causing the inlet valve of the piezoelectric pump to open and the outlet valve to close , the liquid in the accumulator enters the pump cavity, and a working cycle is completed so far. When the piezoelectric vibrator works continuously under the action of alternating voltage, the pulsating fluid output by the piezoelectric pump pushes the piston of the hydraulic cylinder to move in a straight line. Through the control of the reversing valve, the hydraulic cylinder piston can move forward, backward, swing or self-lock.

In another embodiment of the present utility model, the piezoelectric pump includes at least one piezoelectric stack vibrator, a pump chamber membrane, a rigid top block, and a pair of shut-off valves. When the piezoelectric stack vibrator is stretched and deformed under the action of alternating voltage, the volume of the pump chamber and the fluid pressure are changed through the rigid top block and the diaphragm of the pump chamber, and then the opening and closing of the one-way valve are pushed to realize the one-way, continuous flow.

In another embodiment of the present utility model, the piezoelectric pump includes at least one piezoelectric wafer vibrator and a pair of shut-off valves. When the piezoelectric wafer vibrator is bent and deformed under the action of the alternating voltage, the volume of the pump cavity and the fluid pressure will change, thereby promoting the opening and closing of the one-way valve to realize the continuous output of the fluid.

The utility model proposes a piezoelectric hydraulic linear motor that combines piezoelectric ceramic drive and hydraulic transmission technology, that is, the micro deformation and high-frequency vibration of the piezoelectric body are converted into regular straight lines of the hydraulic cylinder piston by using the method of circulating liquid through the piezoelectric pump. sports. The motor has the characteristics of fast response of piezoelectric elements, no electromagnetic interference, easy control, simple structure, small size, etc.; it also has the characteristics of high energy density, large motion stroke, high output pressure, and no impact of hydraulic transmission. Compared with traditional hydraulic actuators, it has simple structure and small volume, and can be used alone or as a standard component of complex systems, suitable for robots, micro systems and remote control systems; compared with existing piezoelectric linear motors, it is The advantage is that it can obtain a large output force and motion stroke at the same time, and realize two-way control of force and displacement.

The utility model has the advantages of novel structure, using the fluid medium to transmit power, and can effectively convert the micro-amplitude reciprocating vibration of the piezoelectric ceramic into the macroscopic linear motion of the piston of the hydraulic cylinder to obtain a larger driving force and motion stroke, and can Precise drive and control are realized by accumulating one drop at a time; at the same time, the piezoelectric hydraulic motor has a simple structure and control, small size, and good sealing performance, and can be used as a marking component.

Description of drawings

Fig. 1 is the structural representation of the utility model piezoelectric hydraulic linear motor;

Fig. 2 is a structural schematic diagram of the utility model piezoelectric stack pump;

Fig. 3 is the structural representation of the utility model piezoelectric wafer pump;

Detailed ways

The inlet of the piezoelectric pump is connected to the accumulator through a pipeline, and the accumulator is also connected to a reversing valve through a pipeline, and the reversing valve is connected to the outlet of the piezoelectric pump through a pipeline, and the reversing valve is also connected through a pipeline The road is connected with the cavity of the hydraulic cylinder; the reversing valve adopts a 3-position 4-way valve.

As shown in Figure 1, the piezoelectric pump 1, the reversing valve 2, the hydraulic cylinder 3 and the accumulator 4 are connected into a closed system through pipelines; the accumulator is connected with the inlet of the piezoelectric pump, and the The reversing valve is a 3-position, 4-way valve; when the piezoelectric pump 1 is started, the movement state of the hydraulic cylinder piston 301 is changed by adjusting the position of the reversing valve 3: when the reversing valve 2 is closed, it is at 202 position, the fluid output by the piezoelectric pump 1 returns directly to the pump chamber through the reversing valve 2, no fluid enters or flows out of the hydraulic cylinder chambers 302 and 303, and the hydraulic cylinder piston rod 301 is in a locked state; the lower end of the reversing valve 2 is connected , at position 201, the outlet of the piezoelectric pump communicates with the cavity 303 of the hydraulic cylinder, the inlet of the piezoelectric pump communicates with the cavity 302 of the hydraulic cylinder, and the piston rod 301 of the hydraulic cylinder moves downward; on the contrary, the upper end of the reversing valve 2 When it is connected, it is at position 203, the inlet and outlet of the piezoelectric pump communicate with the cavities of 303 and 302 of the hydraulic cylinder respectively, and the piston 301 of the hydraulic cylinder moves upward.

As shown in Figure 2, the piezoelectric pump can be driven by a piezoelectric stack vibrator, which is a piezoelectric stack pump. The piezoelectric stack pump consists of a pump body 101, a piezoelectric stack 102, a rigid top block 103, and an elastic diaphragm 104. , And shut-off valves 106 and 107 constitute. The pump body 101 and the elastic diaphragm 104 together form a pump cavity 105 . When the piezoelectric stack vibrator is extended under the action of the external alternating voltage, the diaphragm of the pump chamber is pushed to reduce the volume of the pump chamber 105 and increase the fluid pressure in the pump chamber, the outlet valve 106 is opened, the inlet valve 107 is closed, and the fluid flows from the outlet On the contrary, after the alternating voltage is reversed, the piezoelectric stack vibrator 101 is shortened and the volume of the pump chamber 105 is increased, resulting in a decrease in fluid pressure, the outlet valve 106 is closed, the inlet valve 107 is opened, and the fluid enters the pump chamber.

As shown in FIG. 3 , the piezoelectric pump can be driven by a piezoelectric wafer vibrator, and is a piezoelectric wafer pump. The piezoelectric wafer pump is composed of a pump body 108 , a piezoelectric wafer vibrator 109 and stop valves 111 and 112 . The pump body 108 and the piezoelectric wafer vibrator 109 together form a pump cavity 110 . When the piezoelectric wafer vibrator bends and deforms into the pump chamber under the action of the external alternating voltage to reduce the volume of the pump chamber 110, the fluid pressure in the pump chamber 110 increases, the outlet valve 111 opens, the inlet valve 112 closes, and the fluid flows from The outlet flows out; on the contrary, after the voltage is reversed, the piezoelectric wafer vibrator bends out of the pump chamber to increase the volume of the pump chamber 105, the fluid pressure in the pump chamber decreases, the outlet valve 111 is closed, the inlet valve 112 is opened, and the fluid enters the pump chamber.

Claims (6)

1, a kind of piezoelectric hydraulic linear motor, it is characterized in that: the inlet of piezoelectric pump is connected by pipeline with accumulator, this accumulator also is connected with selector valve by pipeline, and this selector valve is connected by pipeline with the piezoelectricity delivery side of pump, and this selector valve also is connected with the cavity of oil hydraulic cylinder.

2, piezoelectric hydraulic linear motor according to claim 1 is characterized in that: this selector valve adopts 34 logical valves.

3, piezoelectric hydraulic linear motor according to claim 1 and 2 is characterized in that: piezoelectric pump adopts piezoelectric stack pump.

4, piezoelectric hydraulic linear motor according to claim 1 and 2 is characterized in that: piezoelectric pump adopts the piezoelectric chip pump.

5, piezoelectric hydraulic linear motor according to claim 3 is characterized in that: piezoelectric pump adopts 1～10 piezoelectric stack oscillator.

6, piezoelectric hydraulic linear motor according to claim 4 is characterized in that: piezoelectric pump adopts 1～10 piezoelectric chip oscillator.

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