CN110259670B

CN110259670B - Driver

Info

Publication number: CN110259670B
Application number: CN201910509385.7A
Authority: CN
Inventors: 孙健; 冷劲松; 刘彦菊; 周宝; 徐渠鳗
Original assignee: Harbin Institute of Technology
Current assignee: Harbin Institute of Technology
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-11-27
Anticipated expiration: 2039-06-13
Also published as: CN110259670A

Abstract

The invention provides a driver, which comprises a driver shell, wherein an oil outlet and an oil inlet are formed in the outer wall of the driver shell, a hydraulic assembly and a piezoelectric driving assembly are arranged in the driver shell, and a closed working cavity is formed between the hydraulic assembly and the piezoelectric driving assembly; the hydraulic assembly comprises an oil inlet pipe, an oil outlet pipe and a check valve assembly, the oil inlet pipe is communicated with the oil inlet, and the oil outlet pipe is communicated with the oil outlet; the one-way valve assembly comprises an inlet one-way valve and an outlet one-way valve, and the inlet one-way valve limits the fluid flowing from the oil inlet pipe to the working cavity; an outlet check valve restricts fluid flow from the working chamber to the flowline. According to the driver provided by the invention, after the piezoelectric driving assembly is connected with the high-frequency forward sine alternating voltage, the piezoelectric driving assembly changes the pressure on the fluid in the working cavity, and the valve plate structure of the one-way valve assembly can form resonance to promote the oil outlet pipe to suck the fluid from the working cavity and output the fluid through the oil outlet, so that high-frequency driving is realized.

Description

Driver

Technical Field

The invention relates to the technical field of piezoelectric hydraulic pressure, in particular to a driver.

Background

The shape change of the conventional aircraft wing generally uses a hinge, and a motor drive is required, and the motor has large weight, so that a small driver becomes a key point for breaking through technical barriers. In recent years, the rapid development of smart materials has provided a new approach to the design and development of small drives with superior performance. The principle of the driver is that fluid is filled in a designed pump cavity, and the fluid is electrified to circularly flow to generate pressure and flow output and finally converted into certain driving force to realize the driving effect. The high-power energy-saving type air conditioner has the characteristics of small volume, large energy, high reliability and the like, and therefore has wide application prospects in the fields of aerospace, mechanical construction, precise medical treatment and the like.

The conventional piezoelectric ceramic driver cannot work under the resonance frequency due to the hysteresis of the valve, so that the conventional piezoelectric ceramic driver is not suitable for high-frequency driving. Therefore, a piezoelectric ceramic actuator which can achieve both high-frequency driving and high output power and energy density is required.

Disclosure of Invention

The invention solves the problems that: the existing piezoelectric ceramic driver can not adapt to the problem of high-frequency driving.

In order to solve the problems, the invention provides a driver, which comprises a driver shell, wherein an oil outlet and an oil inlet are formed in the outer wall of the driver shell; a hydraulic assembly and a piezoelectric driving assembly connected with one end of the hydraulic assembly are arranged in the driver shell, and a closed working cavity is formed between the hydraulic assembly and the piezoelectric driving assembly; the hydraulic assembly comprises an oil inlet pipe, an oil outlet pipe and a check valve assembly, the oil inlet pipe is communicated with the oil inlet, and the oil outlet pipe is communicated with the oil outlet; the check valve assembly comprises an inlet check valve and an outlet check valve, the inlet check valve is connected with the oil inlet pipe and the working cavity, and the inlet check valve limits fluid to flow from the oil inlet pipe to the working cavity; the outlet one-way valve is connected with the oil outlet pipe and the working cavity, and the outlet one-way valve limits fluid to flow from the working cavity to the oil outlet pipe; the piezoelectric driving assembly is suitable for converting the electric energy transfer port one-way valve and the outlet one-way valve into displacement output so as to adjust the pressure in the working cavity and control the opening and closing of the inlet one-way valve and the outlet one-way valve.

Optionally, the entry check valve with the export check valve all includes the valve block, the valve block is located the disk seat that is equipped with the valve opening, just the valve block can cover the valve opening, the valve block includes free end and stiff end, the stiff end is trapezium structure, trapezium structure's minor flank side is connected with the free end, trapezium structure's major flank side with the disk seat is connected.

Optionally, the check valve assembly further includes an upper valve and a lower valve, the upper valve is connected to the lower valve through the valve seat, the upper valve is connected to the oil inlet pipe and the oil outlet pipe, and a working cavity is formed between the lower valve and the piezoelectric assembly.

Optionally, the inlet check valve further comprises a first inflow hole disposed in the upper valve and a first cavity disposed in the lower valve; the valve plate is clamped between the first inflow hole and the first cavity and can deform towards the direction of the first cavity.

Optionally, the outlet check valve further comprises a second cavity arranged on the upper valve and a second inflow hole arranged on the lower valve; the valve plate is clamped between the second inflow hole and the second cavity and can deform towards the second cavity.

Optionally, the area of the first inflow hole and the area of the second inflow hole are smaller than the area of the valve plate, and the shapes of the first cavity and the second cavity are matched with the shape of the valve plate.

Optionally, the oil inlet pipe and the bottom end of the oil outlet pipe are both provided with annular grooves, and the annular grooves are used for connecting sealing elements.

Optionally, the piezoelectric driving assembly includes a driving structure and piezoelectric ceramics connected to the driving structure, and in the working state of the piezoelectric ceramics, the driving structure moves axially along the working cavity to change the volume of the working cavity, so as to pressurize or generate negative pressure in the working cavity.

Optionally, a sealing member is further disposed between the driving structure and the inner wall of the driver housing.

Optionally, the piezoelectric driving assembly further comprises a hoop, and the hoop is sleeved on the piezoelectric ceramic outer wall.

Optionally, the driver housing includes a first housing and a second housing, the first housing is detachably connected to the second housing, the hydraulic assembly is disposed in the first housing, and the piezoelectric driving assembly is disposed in the second housing.

Optionally, the outer wall of the first shell is further provided with mounting holes which are respectively communicated with the oil inlet pipe, the oil outlet pipe and the working cavity, and the mounting holes are detachably connected with sensors.

Optionally, the outer wall of the second shell is provided with a heat dissipation groove, and the heat dissipation groove is arranged along the length direction of the second shell.

Compared with the prior art, the driver provided by the invention has the following advantages:

(1) according to the driver provided by the invention, after the piezoelectric driving assembly is connected with the high-frequency forward sine alternating voltage, the piezoelectric driving assembly changes the pressure on the fluid in the working cavity, and the valve plate structure of the one-way valve assembly can form resonance to promote the oil outlet pipe to suck the fluid from the working cavity and output the fluid through the oil outlet, so that high-frequency driving is realized.

According to the driver provided by the invention, by optimizing the valve plate structure, the deformation amount of the valve plate is larger, the single liquid pumping amount is larger, and the output flow of the driver is increased; meanwhile, compared with the existing rectangular valve plate, the trapezoidal valve plate adopted by the invention has better rebound resilience and responsiveness in vibration and is more suitable for high-frequency vibration.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an embodiment of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 is an exploded view of a driver according to the present invention;

FIG. 2 is a cross-sectional view of the actuator of the present invention;

FIG. 3 is a partial schematic view of the actuator according to the present invention;

FIG. 4 is a schematic view of a partial structure of a first housing according to the present invention;

FIG. 5 is a schematic view of a valve seat according to the present invention;

FIG. 6 is a schematic structural view of a one-way valve assembly according to the present invention;

FIG. 7 is a schematic view of a conventional check valve reed according to the present invention;

fig. 8(a) is a relation (2.35Mpa) between the output flow and the voltage of the rectangular valve plate driver, and fig. 8(b) is a relation (2.35Mpa) between the output flow and the voltage of the trapezoidal valve plate driver;

FIG. 9(a) is a graph (2.35MPa) showing the relationship between the pressure difference of the inlet/outlet pipeline of the rectangular valve plate driver and the driving voltage, and FIG. 9(b) is a graph (2.35MPa) showing the relationship between the pressure difference of the inlet/outlet pipeline of the trapezoidal valve plate driver and the driving voltage.

Description of reference numerals:

1-a driver shell, 11-a first shell, 111-an oil inlet, 112-an oil outlet, 113-a mounting hole, 114-a counter bore, 12-a second shell, 2-a hydraulic assembly, 21-an oil inlet pipe, 22-an oil outlet pipe, 23-a check valve assembly, 231-an inlet check valve, 232-an outlet check valve, 233-an upper valve, 2331-a first inlet hole, 2332-a second cavity, 2333-a second limiting hole, 234-a valve seat, 235-a lower valve, 2351-a first cavity, 2352-a second inlet hole, 2353-a first limiting hole, 236-a valve plate, 2361-a free end, 2362-a fixed end, 24-an annular groove, 25-a working chamber, 3-a piezoelectric driving assembly, 31-a driving structure, 311-a connecting piece, 312-sealing diaphragm, 313-piston, 32-piezoceramic, 33-back cover, 34-clip, 35-seal, 4-sensor, 5-heat sink, 6-fastener, 7-check valve reed.

Detailed Description

It should be noted that the embodiments and features of the embodiments may be combined with each other without conflict.

In addition, the terms "upper", "lower", "left", "right", "vertical", "horizontal", and the like referred to in the embodiments of the present invention indicate orientation or positional relationship based on the orientation or positional relationship shown in the drawings; "length," "width," "thickness," "top," "bottom," "inner," "outer," and the like are merely used to facilitate describing the invention and to simplify the description, and do not indicate or imply that the device or element so referred to must be oriented, constructed, and operated in a particular orientation, and therefore should not be considered limiting of the invention.

It should be noted that, a hydraulic cylinder is connected between the oil inlet and the oil outlet of the driver, and the hydraulic cylinder is generally pushed by oil pressure between the oil inlet and the oil outlet to do work. After the assembly connection is completed, all cavities of the driver are filled with hydraulic oil, and meanwhile, an oil inlet is also connected with an oil pump in order to facilitate the normal work of an oil way.

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

Referring to fig. 1 to 6, a driver includes a driver housing 1, an oil outlet 112 and an oil inlet 111 are provided on an outer wall of the driver housing 1; a hydraulic component 2 and a piezoelectric driving component 3 connected with one end of the hydraulic component 2 are arranged in the driver shell 1, and a closed working cavity 25 is formed between the hydraulic component 2 and the piezoelectric driving component 3; the hydraulic assembly 2 comprises an oil inlet pipe 21, an oil outlet pipe 22 and a check valve assembly 23, wherein the oil inlet pipe 21 is communicated with the oil inlet 111, and the oil outlet pipe 22 is communicated with the oil outlet 112; the check valve assembly 23 comprises an inlet check valve 231 and an outlet check valve 232, the inlet check valve 231 is connected with the oil inlet pipe 21 and the working chamber 25, and the inlet check valve 231 limits the flow of the fluid from the oil inlet pipe 21 to the working chamber 25; the outlet check valve 232 connects the flow line 22 and the working chamber 25, and the outlet check valve 232 restricts the flow of fluid from the working chamber 25 to the flow line 22; piezoelectric drive assembly 3 is adapted to convert electrical energy to a displacement output to regulate pressure in working chamber 25, controlling the opening and closing of inlet check valve 231 and outlet check valve 232.

The actuator provided by the embodiment of the invention utilizes the periodic bending deformation of the piezoelectric material to drive and change the volume of the working cavity 25, so that the pressure in the working cavity 25 is changed, and the directional flow of fluid is realized under the matching opening and closing of the inlet and outlet one-way valves 232.

Inlet check valve 231 and outlet check valve 232 all include valve block 236, and valve block 236 is located the disk seat 234 that is equipped with the valve opening, and valve block 236 can cover the valve opening, and valve block 236 includes free end 2361 and stiff end 2362, and stiff end 2362 is the trapezium structure, and the short avris of trapezium structure is connected with free end 2361, and the long avris of trapezium structure is connected with disk seat 234.

Referring to fig. 5, specifically, the number of the valve 233 pieces on the valve seat 234 is 2, and 2 valve pieces 236 correspond to the oil inlet pipe 21 and the oil outlet pipe 22, respectively. The free end 2361 of the valve plate 236 is a circular sheet structure with a notch, the fixed end 2362 is a trapezoid structure, the width of the short straight side of the trapezoid structure is L1, the width of the long straight side of the trapezoid structure is L2, the short straight side is connected with the notch of the free end 2361 when L2 is larger than L1, and the long straight side is connected with the valve seat 234. The inlet check valve 231 and the outlet check valve 232 are communicated through deformation of the valve plate 236, when the valve plate 236 deforms to expose the valve hole, the plane of the valve seat 234 and the plane of the valve plate 236 form an acute angle, that is, the valve port is opened, and fluid can flow into or out of the valve port.

The width of the short straight edge of the trapezoid structure is L1, the width of the long straight edge of the trapezoid structure is L2, the value range of the short straight edge and the value range of the long straight edge of the trapezoid structure are 1.2-1.5 mm, and the value range of L1/L2 is 0.8-0.9. According to the practice of the inventor, when both L1 and L2 are smaller than 1.2mm, the connecting area of the valve plate 236 and the valve seat 234 is small, and the risk of breaking or failure of the valve plate 236 is easy to occur in long-time vibration; when both L1 and L2 are larger than 1.5mm, the areas of the corresponding first chamber 2351 and second chamber 2332 become larger, and the through hole is too large, which may result in a reduction in the structural strength of the upper valve 233 and the lower valve 235 and a reduction in the lifespan of the actuator.

Correspondingly, the force for supporting the free end 2361 falls on the short straight edge of the fixed end 2362, when the value range of L1/L2 is less than 0.8, the difference between the lengths of the long straight edge and the short straight edge of the fixed end 2362 is too large, the connecting area between the fixed end 2362 and the free end 2361 is small, and in the long-time vibration of the valve plate 236, the pressure borne by the short straight edge of the fixed end 2362 is too large, so that the free end 2361 is easy to break; when the value range of L1/L2 is larger than 0.9, the lengths of the long straight side and the short straight side of the fixed end 2362 tend to be equal, and the effects of improving the natural frequency and increasing the output flow of the driver cannot be achieved.

Referring to fig. 7, as shown in the check valve reed 7 of the conventional actuator, a fixed end 2362 of the conventional check valve reed 7 has a rectangular structure, and a width of a side of the fixed end 2362 connected to a free end 2361 is equal to a width of an opposite side thereof. For convenience of understanding, the conventional check valve reed 7 is referred to as a rectangular valve plate, and the valve plate 236 provided by the embodiment of the present invention is referred to as a trapezoidal valve plate.

Compare with the rectangle valve block, trapezoidal valve block has better resilience performance in the vibration, and the derivation based on structure dynamics simultaneously, natural frequency is higher during trapezoidal valve block vibration, therefore trapezoidal valve block can have better response, more can adapt to high frequency vibration.

Fig. 8(a) is a graph (2.35Mpa) of the relationship between the output flow and the voltage of the rectangular valve plate driver, and fig. 8(b) is a graph (2.35Mpa) of the relationship between the output flow and the voltage of the trapezoidal valve plate driver, and it can be seen from the graph that, under a driving frequency of 200Hz, the output flow of the rectangular valve plate driver at a driving voltage of 1000v is 2.7ml/s, while the output flow of the trapezoidal valve plate driver at a driving voltage of 1000v is 3.0ml/s, and under the same condition, the output flow of the trapezoidal valve plate driver is greater than that of the rectangular valve plate driver, and it can be expected that the pressure of the trapezoidal valve plate lifted by the pump is also greater than that of the rectangular valve.

Fig. 9(a) is a graph (2.35Mpa) of the relationship between the pressure difference of the oil outlet and inlet pipelines of the rectangular valve plate driver and the driving voltage, and fig. 9(b) is a graph (2.35Mpa) of the relationship between the pressure difference of the oil outlet and inlet pipelines of the trapezoidal valve plate driver and the driving voltage, where the pressure difference of the oil inlet and outlet pipelines of the driver is the difference between the pressure of the oil outlet 112 and the pressure of the oil inlet 111 in the working state of the driver.

As can be seen from FIG. 9, under a driving frequency of 200Hz and a driving voltage of 1000v, the pressure difference between the oil inlet and outlet pipelines of the rectangular valve plate driver is 4.0MPa, and the pressure difference between the oil inlet and outlet pipelines of the trapezoidal valve plate driver is 5.3MPa, which proves that under the same conditions, the pressure difference between the oil inlet and outlet pipelines of the trapezoidal valve plate driver is greater than that of the rectangular valve plate driver. Therefore, according to the driver provided by the embodiment of the invention, by optimizing the structure of the valve plate 236, in the working process, the deformation amount of the valve plate 236 is large (the valve port opening displacement is large), the single liquid suction amount is large, and the output flow is large. And because in actual use, if contain bubble or impurity in the fluid, the great valve port jam that can also avoid of single liquid suction volume guarantees the normal work of driver.

Wherein, driver casing 1 includes first casing 1 and second casing 12, and first casing 1 and second casing 12 dismantlement formula link together, and wherein, first casing 1 and second casing 12 all are equipped with the connecting portion of taking counter bore 114, and the counter bore 114 on both connecting portions passes through bolt fixed connection, and from this, be convenient for loading and unloading and maintenance between the two. The hydraulic assembly 2 is arranged in the first shell 1, and the piezoelectric driving assembly 3 is arranged in the second shell 12; under the assembly state of the first shell 1 and the second shell 12, the joint of the first shell 1 and the second shell 12 is sealed, and a part of the piezoelectric driving component 3 extends into the hydraulic component 2, and a closed working cavity 25 is formed between the piezoelectric driving component and the hydraulic component 2, so that when the working cavity 25 is filled with fluid, the part of the piezoelectric driving component 3 extending into the working cavity 25 can move along the axial direction of the working cavity 25, and pressure is applied to the fluid in the working cavity 25, thereby controlling the opening and closing of the inlet check valve 231 and the outlet check valve 232.

Referring to fig. 3, the check valve assembly 23 further includes an upper valve 233 and a lower valve 235, the upper valve 233 is connected to the lower valve 235 through a valve seat 234, the upper valve 233 is connected to the oil inlet pipe 21 and the oil outlet pipe 22, and a working chamber 25 is formed between the lower valve 235 and the piezoelectric assembly. Specifically, since the inlet check valve 231 connects the oil inlet pipe 21 and the working chamber 25, and restricts the flow of fluid from the oil inlet pipe 21 to the working chamber 25; the outlet check valve 232 connects the flowline 22 to the working chamber 25 and restricts fluid flow from the working chamber 25 to the flowline 22. The upper valve 233 is connected with the oil inlet pipe 21 and the oil outlet pipe 22, so that the inlet check valve 231 and the outlet check valve 232 are integrated, that is, although the inlet check valve 231 and the outlet check valve 232 correspond to different oil pipes, the check valve assembly 23 has the functions of one-way oil inlet and one-way oil outlet, the overall structure is optimized, and the structure of the driver is more compact and simple.

The inlet check valve 231 further includes a first inflow hole 2331 disposed at the upper valve 233 and a first cavity 2351 disposed at the lower valve 235; the valve plate 236 is clamped between the first inflow hole 2331 and the first chamber 2351, and can be deformed toward the first chamber 2351. The inlet check valve 231 comprises a first inflow hole 2331, a valve plate 236 and a first cavity 2351 which are fixedly connected from top to bottom in sequence, when the valve plate 236 deforms towards the direction of the first cavity 2351, the valve port is opened downwards, fluid flowing out of the oil inlet cavity flows towards a second cavity 2332 through the valve port after passing through the first inflow hole 2331, and then enters the working cavity 25 through the second cavity 2332, so that the one-way oil absorption function is realized.

The outlet check valve 232 further includes a second chamber 2332 disposed at the upper valve 233 and a second inlet orifice 2352 disposed at the lower valve 235; the valve plate 236 is sandwiched between the second inflow hole 2352 and the second chamber 2332 and is deformable toward the second chamber 2332. That is, the outlet check valve 232 includes the second chamber 2332, the valve plate 236 and the second inflow hole 2352 which are fixedly connected in sequence from top to bottom, when the valve plate 236 deforms towards the second chamber 2332, the valve port is opened upwards, the fluid in the working chamber 25 enters the second inflow hole 2352 from the working chamber 25 under the action of pressure, and flows upwards towards the first chamber 2351 through the valve port, enters the oil outlet chamber through the second chamber 2332, and flows out from the oil outlet 112 under the action of pressure, so that the one-way oil outlet function is realized.

It is understood that the areas of the first inflow hole 2331 and the second inflow hole 2352 are smaller than the area of the valve plate 236, and the shapes of the first chamber 2351 and the second chamber 2332 are matched with the shape of the valve plate 236. Since the inlet check valve 231 is used to limit the flow of fluid into the oil pipe 21 to the working chamber 25, that is, the valve plate 236 of the inlet check valve 231 cannot deform toward the oil pipe 21, the upper valve 233 acts as a stop for the valve plate 236. If the area of the first inflow hole 2331 is larger than that of the valve plate 236, the valve plate 236 may deform toward the first inflow hole 2331, and thus the unidirectional oil absorption function cannot be realized. When the area of the first inflow hole 2331 is much smaller than that of the valve plate 236, it is not only convenient for the inflow of fluid but also prevents the valve plate 236 from being deformed toward the oil inlet pipe 21.

Of course, if the area of the first inflow hole 2331 is larger than that of the valve plate 236 and the first inflow hole 2331 is staggered with respect to the valve plate 236, the stop function can be achieved, but the single flow of the fluid is reduced, which is not beneficial to the operation of the driver.

Accordingly, since the inlet check valve 231 is used to limit the flow of the fluid working chamber 25 to the outlet pipe 22, that is, the valve plate 236 of the outlet check valve 232 cannot be deformed toward the working chamber 25, at this time, the lower valve 235 acts as a stop for the valve plate 236. If the area of the second inflow hole 2352 is larger than that of the valve sheet 236, the valve sheet 236 may deform toward the second inflow hole 2352, so that the one-way oil outlet function may not be realized.

The shapes of the first chamber 2351 and the second chamber 2332 may or may not match with the shape of the valve plate 236, as long as the valve plate 236 can deform toward the first chamber 2351 or the second chamber 2332 in the operating state. The preferred matching of the embodiments of the invention, under the design, can facilitate the deformation of the valve plate 236 to the maximum extent under the condition of not influencing the structural strength of the valve seat 234, and ensure that the valve port is opened by a large displacement.

It is understood that, since the areas of the first and

second chambers

2351 and 2332 are larger than the areas of the first and

second inflow holes

2331 and 2352, in order to make the fluid flow more continuously and smoothly, the first and

second chambers

2351 and 2332 are through holes provided on the lower and

upper valves

235 and 233 through which the fluid may pass, and the aperture of one end of the first and

second chambers

2351 and 2332 adjacent to the valve plate 236 is larger than that of the opposite end. That is, the first cavity 2351 may be regarded as a recess portion disposed on the lower valve 235, and a through hole is formed at a bottom end of the recess portion. By the arrangement, a deformation space can be reserved for the valve plate 236, and the fluid discharge and suction cannot be influenced by overlarge aperture.

In the embodiment of the present invention, the hole provided on the first chamber 2351 is defined as the first defining hole 2353, and the hole provided on the second chamber 2332 is defined as the second defining hole 2333. In the open state of the inlet check valve 231, the fluid flows through the valve in sequence including: a first inflow hole 2331, a valve plate 236, a first cavity 2351 and a first defining hole 2353; in the open state of the outlet check valve 232, the fluid flows through the valve in sequence including: a second inflow hole 2352, a valve plate 236, a second chamber 2332, and a second limiting hole 2333.

In order to reduce the head loss of the fluid when the fluid flows through the inflow check valve and the outflow check valve, namely to reduce the pressure loss coefficient of the fluid, guide angles are arranged at the positions where the areas of the fluid flow are changed. As shown in fig. 3, a chamfer is provided at an end of the second inflow hole 2352 adjacent to the working chamber 2 to facilitate inflow of the fluid. Of course, chamfers may be provided at other positions, which are not illustrated herein.

In addition, the annular grooves 24 are formed at the bottom ends of the oil inlet pipe 21 and the oil outlet pipe 22, and the annular grooves 24 are used for connecting the sealing elements 35. The center line of the annular groove 24 is aligned with the center line of the inlet pipe 21 or the outlet pipe 22. The sealing element 35 can prevent the oil inlet pipe 21 and the oil outlet pipe 22 from being communicated, and meanwhile, the oil inlet pipe 21 and the oil outlet pipe 22 can be prevented from leaking oil, and the sealing performance of the oil circuit system is guaranteed.

Specifically, the piezoelectric driving assembly 3 includes a driving structure 31 and a piezoelectric ceramic 32 connected to the driving structure 31, and in an operating state of the piezoelectric ceramic 32, the driving structure 31 moves axially along the working cavity 25 to change the volume of the working cavity 25, so as to pressurize or generate a negative pressure in the working cavity 25.

The driving structure 31 comprises a connecting piece 311, a sealing spacer 312 and a piston 313, wherein the connecting piece 311 is fixedly connected with the piston 313 through the sealing spacer 312, and the piston 313 is fixedly connected with one end of the piezoelectric ceramic 32. Specifically, the piston 313 is fixed on the piezoelectric ceramic 32 by screw connection, four screws fix the connecting piece 311 on the piston 313, and the sealing spacer 312 is fixed between the connecting piece 311 and the piston 313, so that when the piezoelectric ceramic 32 works, high-frequency micro displacement is transmitted to the working oil cavity through the driving structure 31.

A seal 35 is also provided between the drive structure 31 and the inner wall of the drive housing 1. That is, the seal 35 is connected between the seal spacer 312 and the first housing 1. The sealing element 35 is an annealed red copper sealing ring, the annealed red copper is soft in material, and the sealing element 35 is compacted to achieve a good sealing effect. And because the copper ring is used for sealing, the sealing effect is much higher than that of a cyanogen butadiene rubber ring used for sealing a driver in most of the prior art, so that the oil pressure of the discharged oil can be further stably promoted.

In addition, in order to reduce the overall mass of the driver, the driver shell 1 can be made of hard aluminum alloy; in order to enhance the structural strength of the main components of the actuator, the check valve assembly 23 and the actuating structure 31 are made of stainless steel, and preferably, the valve plate 236 is made of spring steel with a thickness of 0.2 mm.

The piezoelectric driving assembly 3 further includes a rear cover 33, and the rear cover 33 is detachably connected to an end of the piezoelectric ceramic 32 away from the driving structure 31. The back cover 33 and the second shell 12 cooperate to limit the translation and rotation of the piezoelectric ceramics 32 in the longitudinal plane, thereby improving the working efficiency of the piezoelectric ceramics 32. Meanwhile, the rear cover 33 is detachably connected, so that the height of the working cavity 25 can be adjusted, and different working conditions can be met.

In the embodiment of the present invention, the height of the working chamber 25 is 0.8-1.0 mm, preferably 0.9 mm. If the height of the working cavity 25 exceeds 1.0mm, the pressure required in the working cavity 25 when the one-way oil outlet function is realized is improved, so that the oil outlet quantity of the driver is reduced, and the using effect of the driver is adversely affected.

The piezoelectric driving component 3 further comprises a hoop 34, and the hoop 34 is sleeved on the outer wall of the piezoelectric ceramic 32. The clip 34 is located between the piezoelectric ceramic 32 and the second housing 12, and the clip 34 and the second housing 12 cooperate to limit the translation and rotation of the piezoelectric ceramic 32 in the transverse plane of the second housing 12, thereby improving the installation stability of the piezoelectric ceramic 32.

The outer wall of the first shell 1 is further provided with a mounting hole 113 which is respectively communicated with the oil inlet pipe 21, the oil outlet pipe 22 and the working cavity 25, and the sensor 4 is detachably connected to the mounting hole 113. The sensor 4 is a pressure sensor and is fixed on the outer wall of the first housing 1 by a fastener 6.

The oil inlet cavity and the oil outlet cavity are both connected with the sensor 4, and the working condition and the pressure lifting condition of the piezoelectric pump and the pressure difference between the two ends of the oil outlet 112 and the oil inlet 111 can be directly known through a computer.

The sensor 4 is connected inside the working chamber 25, and can directly detect the pressure change of the liquid in the working chamber 25, thereby judging the service life and fatigue degree of the check valve plate 236 and whether the check valve plate needs to be replaced.

The outer wall of the second shell 12 is provided with a heat dissipation groove 5, and the heat dissipation groove 5 is arranged along the length direction of the second shell 12. The number of the heat dissipation grooves 5 may be multiple, and a plurality of the heat dissipation grooves 5 are distributed along the periphery of the outer wall of the second housing 12. The piezoelectric ceramics 32 generate much heat during working, and the heat dissipation groove 5 is arranged to dissipate heat well, so that the piezoelectric ceramics 32 are protected; meanwhile, under the good condition of heat dissipation, the temperature of the heat dissipation groove 5 is close to that of the piezoelectric ceramic 32, and the sensor 4 can be installed on the heat dissipation groove 5, so that the temperature of the piezoelectric ceramic 32 is monitored, and the driver is guaranteed to be driven to work on the premise of safety.

When the driver provided by the embodiment of the invention works, the driver comprises two steps of oil outlet and oil inlet:

applying high-frequency sine forward voltage to the piezoelectric ceramic 32, wherein the piezoelectric ceramic 32 deforms due to the inverse piezoelectric effect of the piezoelectric ceramic 32, the piston 313 is driven by the deformation through the piezoelectric ceramic 32 to move upwards, the displacement is transmitted to the working cavity 25, fluid in the working cavity 25 is extruded, the pressure of the fluid in the cavity is increased, the valve plate 236 of the inflow check valve cannot deform towards the first cavity 2351, and the inflow check valve is closed; meanwhile, under the action of fluid pressure, the valve plate 236 of the outflow check valve deforms towards the second chamber 2332, and the outflow check valve opens; in the one-way flow condition, fluid passes through the second chamber 2332 into the flow line 22 and out the outlet port 112.

When the applied high-frequency sinusoidal positive voltage starts to decrease, the deformation of the piezoelectric ceramic 32 starts to recover, the driving piston 313 retracts to reduce the pressure in the working chamber 25, fluid flows into the oil inlet pipe 21 from the oil inlet 111 and enters the first inflow hole 2331, under the negative pressure action of the working chamber 25, the valve plate 236 of the inflow check valve deforms towards the first cavity 2351, and the inflow check valve opens; meanwhile, since the valve plate 236 of the outflow check valve cannot deform toward the second chamber 2332, the outflow check valve is closed; at this time, the one-way oil suction state is achieved, and the fluid enters the working chamber 25 after passing through the first chamber 2351.

The basic working process of the driver provided by the embodiment of the invention is as follows:

firstly, filling all cavities in a driver with hydraulic oil by using a pressurizing pump, and keeping a certain pressure; then, the fluid enters the oil inlet pipe 21 through the oil inlet hole, an energy accumulator is arranged in the oil inlet pipe 21 to keep the side pressure constant, and then the fluid flows into the one-way valve and enters the working cavity 25; when the piezoelectric ceramic 32 works, the piston 313 can be pushed to reciprocate, fluid is compressed in the working cavity 25 and enters the oil outlet pipe 22 through the outflow one-way valve, and finally, the driven fluid enters the hydraulic pipeline through the oil outlet 112. A hydraulic cylinder is connected between the oil outlet 112 and the oil inlet 111, and at the moment, the hydraulic cylinder can be pushed to do work by the oil pressure between the oil outlet 112 and the oil inlet 111. The above processes are carried out in a reciprocating way, the intracavity circulation of the fluid is realized, when the hydraulic cylinder is pushed to one side, the movement direction of the hydraulic cylinder is changed through the reversing valve, and the piezoelectric ceramic 32 hydraulic pump is driven again to work.

Although the present disclosure has been described above, the scope of the present disclosure is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of the present disclosure, and such changes and modifications will fall within the scope of the present invention.

Claims

1. The driver is characterized by comprising a driver shell (1), wherein an oil outlet (112) and an oil inlet (111) are formed in the outer wall of the driver shell (1); a hydraulic component (2) and a piezoelectric driving component (3) connected with one end of the hydraulic component (2) are arranged in the driver shell (1), and a closed working cavity (25) is formed between the hydraulic component (2) and the piezoelectric driving component (3);

the hydraulic assembly (2) comprises an oil inlet pipe (21), an oil outlet pipe (22) and a check valve assembly (23), the oil inlet pipe (21) is communicated with the oil inlet (111), and the oil outlet pipe (22) is communicated with the oil outlet (112);

the one-way valve assembly (23) comprises an inlet one-way valve (231) and an outlet one-way valve (232), the inlet one-way valve (231) is connected with the oil inlet pipe (21) and the working chamber (25), and the inlet one-way valve (231) limits the fluid to flow from the oil inlet pipe (21) to the working chamber (25); said outlet check valve (232) connecting said flow line (22) and said working chamber (25), said outlet check valve (232) restricting fluid flow from said working chamber (25) to said flow line (22);

the piezoelectric driving component (3) is suitable for converting electric energy into displacement output so as to adjust the pressure in the working cavity (25) and control the opening and closing of the inlet check valve (231) and the outlet check valve (232);

the inlet check valve (231) and the outlet check valve (232) respectively comprise a valve plate (236), the valve plate (236) is located on a valve seat (234) provided with a valve hole, the valve plate (236) can cover the valve hole, the valve plate (236) comprises a free end (2361) and a fixed end (2362), the fixed end (2362) is of a trapezoidal structure, the short side of the trapezoidal structure is connected with the free end (2361), and the long side of the trapezoidal structure is connected with the valve seat (234);

the width of the short straight side of the trapezoid structure is L1, the width of the long straight side of the trapezoid structure is L2, L2 is larger than L1, the value ranges of L1 and L2 are both 1.2-1.5 mm, and the value range of L1/L2 is 0.8-0.9.

2. The actuator of claim 1, wherein the one-way valve assembly (23) further comprises an upper valve (233) and a lower valve (235), the upper valve (233) is connected to the lower valve (235) through the valve seat (234), the upper valve (233) is connected to the oil inlet pipe (21) and the oil outlet pipe (22), and a working chamber (25) is formed between the lower valve (235) and the piezoelectric assembly.

3. The actuator of claim 2, wherein the inlet check valve (231) further comprises a first inflow hole (2331) disposed in the upper valve (233) and a first cavity (2351) disposed in the lower valve (235); the valve plate (236) is clamped between the first inflow hole (2331) and the first cavity (2351) and can deform towards the direction of the first cavity (2351).

4. The actuator of claim 2, wherein the outlet check valve (232) further comprises a second cavity (2332) disposed in the upper valve (233) and a second inlet orifice (2352) disposed in the lower valve (235); the valve plate (236) is clamped between the second inflow hole (2352) and the second cavity (2332) and can deform towards the second cavity (2332).

5. The driver according to claim 3, wherein the area of the first inflow hole (2331) is smaller than the area of the valve plate (236), and the shape of the first cavity (2351) matches the shape of the valve plate (236).

6. The actuator of claim 4, wherein the area of the second inflow hole is smaller than the area of the valve plate (236), and the shape of the second chamber (2332) matches the shape of the valve plate (236).

7. Drive according to any of claims 1-4, characterized in that the oil inlet pipe (21) and the bottom end of the oil outlet pipe (22) are provided with an annular groove (24), which annular groove (24) is used for connecting a seal (35).

8. An actuator according to any one of claims 1 to 4, wherein the piezoelectric drive assembly (3) comprises a drive structure (31) and a piezoelectric ceramic (32) connected to the drive structure (31), and in an operating state of the piezoelectric ceramic (32), the drive structure (31) moves axially along the working chamber (25) to change the volume of the working chamber (25) so as to pressurize or generate a negative pressure in the working chamber (25).

9. An actuator according to claim 8, wherein a seal (35) is further provided between the actuation structure (31) and the inner wall of the actuator housing (1).

10. An actuator according to claim 8, wherein the piezoelectric actuator assembly (3) further comprises a collar (34), the collar (34) being fitted over the outer wall of the piezoelectric ceramic (32).

11. An actuator according to any of claims 1-4, 9-10, wherein the actuator housing (1) comprises a first housing (11) and a second housing (12), the first housing (11) being detachably connected to the second housing (12), the hydraulic assembly (2) being arranged in the first housing (11), and the piezoelectric actuation assembly (3) being arranged in the second housing (12).

12. The actuator according to claim 11, wherein the outer wall of the first housing (11) is further provided with a plurality of mounting holes (113) respectively communicated with the oil inlet pipe (21), the oil outlet pipe (22) and the working chamber (25), and the sensor (4) is detachably connected to the mounting holes (113).

13. The driver according to claim 11, characterized in that the second shell (12) is provided with a heat sink (5) on the outer wall, and the heat sink (5) is arranged along the length direction of the second shell (12).