CN115724135A

CN115724135A - In-plane traveling wave type linear feeding device and working method thereof

Info

Publication number: CN115724135A
Application number: CN202211514719.8A
Authority: CN
Inventors: 王鑫; 王亮; 李赛
Original assignee: Nanjing University of Aeronautics and Astronautics
Current assignee: Nanjing University of Aeronautics and Astronautics
Priority date: 2022-11-30
Filing date: 2022-11-30
Publication date: 2023-03-03

Abstract

The invention discloses an in-plane traveling wave type linear feeding device and a working method thereof, wherein the device comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, first to fourth piezoelectric units, first to second pre-tightening bolts, a piezoelectric bimorph, first to third stoppers and M + N + P adjusting bolts; when the piezoelectric actuator works, a sinusoidal signal U1 is applied to a first piezoelectric transducer, a sinusoidal signal U2 is applied to a second piezoelectric transducer, the frequencies and the voltages of the U1 and the U2 are the same and have a phase difference of pi/4, longitudinal vibration modes of the first piezoelectric transducer and the second piezoelectric transducer are excited, and longitudinal vibration superposition with the phase difference of pi/4 induces a traveling wave mode of a middle beam; under the traveling wave mode, the vibration mode of a single mass point on the middle beam is represented as elliptical motion, so that materials placed on the middle beam move towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point; the reverse transportation of the materials can be realized by adjusting the phase difference between U1 and U2 to-pi/4. The invention has simple structure and high transportation stability.

Description

In-plane traveling wave type linear feeding device and working method thereof

Technical Field

The invention relates to the field of piezoelectric feeders, material conveying and microparticle transportation, in particular to an in-plane traveling wave type linear feeding device and a working method thereof.

Background

The vibration feeding equipment is a common equipment in automatic packaging, has the functions of forming the arraying, sequencing and directional conveying of materials, and has important application value in the production fields of the detection and sealing links of modern precise semiconductor devices, micro mechanical transportation and the like which need automatic precise conveying.

The vibration material conveying device can be divided into an electromagnetic vibration material conveying device and a piezoelectric vibration material conveying device according to a vibration excitation source. Feeding devices adopting electromagnets as driving sources are widely applied to production lines, but the electromagnetic type vibration feeder has the defects of high noise, low energy conversion rate, unsuitability for precise material conveying and the like. With the development of piezoelectric technology, new drivers using piezoelectric materials as driving sources are receiving more and more attention from researchers.

In 1977, researchers of japan special ceramics co., ltd, first proposed a piezoelectric vibration feeder using a rectangular piezoelectric ceramic plate as a driving source. The working principle is that when the piezoelectric vibrator is excited by an alternating excitation signal, the spring piece generates reciprocating bending deformation under the excitation of piezoelectric ceramics due to the inverse piezoelectric effect, and the top plate is induced to generate elliptical motion, so that materials are conveyed.

The conventional linear piezoelectric feeder on the market is added with a mass block on the basis of the piezoelectric vibration feeder, and the vibration amplitude of a top plate is improved through the inertia added by the mass block, so that the conveying effect is improved. When the inertia mass block is not added, the piezoelectric coefficient of the patch type piezoelectric transducer is not high, and the amplitude is small. After the inertia mass block is added, the amplitude is improved, but the instability of material transportation is also increased. Meanwhile, due to the structure, the piezoelectric type vibration feeder can only realize one-way transportation of materials.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides an in-plane traveling wave type linear feeding device and a working method thereof.

The invention adopts the following technical scheme for solving the technical problems:

an in-plane traveling wave type linear feeding device comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, a first piezoelectric unit, a second piezoelectric unit, a fourth piezoelectric unit, a first pretightening bolt, a second pretightening bolt, a piezoelectric bimorph, a first stopper, a second pretightening bolt, a third stopper and M + N + P adjusting bolts, wherein M, N, P are natural numbers which are more than or equal to 1;

the middle beam is a cuboid, and the centers of two ends of the middle beam are respectively provided with a pre-tightening threaded blind hole;

the front beam and the rear beam are of the same structure and are cuboids with the same cross section as the cross section of the middle beam, and the center of one end face is provided with a countersunk through hole;

the first piezoelectric unit, the second piezoelectric unit, the third piezoelectric unit and the fourth piezoelectric unit have the same structure and comprise Q piezoelectric ceramic pieces, wherein Q is a natural number more than or equal to 1; the cross sections of the piezoelectric ceramic piece and the middle beam are the same in shape, and a through hole is formed in the center of the piezoelectric ceramic piece and the middle beam; the Q piezoelectric ceramic pieces are sequentially stacked and are polarized along the thickness direction, and the polarization directions of the adjacent piezoelectric ceramic pieces are opposite;

the first connecting sheet and the second connecting sheet have the same structure, are both rectangular sheet structures and are both vertically arranged, the lower ends of the first connecting sheet and the second connecting sheet are both fixedly connected with the base, and the upper ends of the first connecting sheet and the second connecting sheet are both provided with through holes;

the first pre-tightening bolt sequentially penetrates through the front beam, the first piezoelectric unit, the through hole in the first connecting sheet and the second piezoelectric unit from the countersunk head through hole of the front beam and is in threaded connection with the threaded blind hole at one end of the middle beam, the front beam, the first piezoelectric unit, the first connecting sheet, the second piezoelectric unit and the middle beam are clamped, and the front beam, the first piezoelectric unit, the second piezoelectric unit and the middle beam are coaxial; the second pre-tightening bolt sequentially penetrates through the through holes in the rear beam, the third piezoelectric unit, the second connecting sheet and the fourth piezoelectric unit from the countersunk head through hole of the rear beam and is in threaded connection with the threaded blind hole at the other end of the middle beam, the rear beam, the third piezoelectric unit, the second connecting sheet, the fourth piezoelectric unit and the middle beam are clamped, and the rear beam, the third piezoelectric unit, the fourth piezoelectric unit and the middle beam are coaxial;

the polarization direction of the Q-th piezoelectric ceramic piece in the first piezoelectric unit is opposite to that of the 1 st piezoelectric ceramic piece in the second piezoelectric unit, and the polarization direction of the Q-th piezoelectric ceramic piece in the third piezoelectric unit is opposite to that of the 1 st piezoelectric ceramic piece in the fourth piezoelectric unit;

the adjusting bolt comprises a nut and a stud;

the upper surfaces of the first stopper, the second stopper and the third stopper are respectively provided with M, N and P adjusting grooves, the adjusting grooves are strip-shaped grooves vertical to the middle beam, the adjusting grooves are respectively provided with strip-shaped through grooves vertical to the middle beam, the width of each adjusting groove is larger than the diameter of a nut of the adjusting bolt, and the width of each strip-shaped through groove is smaller than the diameter of the nut of the adjusting bolt and larger than the diameter of a stud of the adjusting bolt;

m + N + P positioning threaded blind holes which correspond to M adjusting grooves on the first stopper, N adjusting grooves on the second stopper and P adjusting grooves on the third stopper one by one are arranged on the upper surface of the middle beam;

the M + N + P adjusting bolts penetrate through the M + N + P adjusting grooves in a one-to-one corresponding mode and are in threaded connection with the M + N + P positioning threaded blind holes in a one-to-one corresponding mode, the first blocking piece, the second blocking piece and the third blocking piece are fixed on the middle beam, a feeding groove is formed between the first blocking piece and the second blocking piece, a discharging groove is formed between the first blocking piece and the third blocking piece, and a returning groove is formed between the second blocking piece and the third blocking piece; an included angle between the backspacing groove and the discharge groove is an acute angle;

one end of the piezoelectric bimorph is fixedly connected with the third retaining piece, and the other end of the piezoelectric bimorph abuts against the second retaining piece and is used for isolating the feed chute and the backspacing chute under the non-driving state to enable the feed chute to be communicated with the discharge chute, and isolating the feed chute and the discharge chute under the driving state to enable the feed chute to be communicated with the backspacing chute.

As a further optimization scheme of the in-plane traveling wave type linear feeding device, Q is 2.

The invention also discloses a working method of the in-plane traveling wave type linear feeding device, which comprises the following steps:

the front beam, the first piezoelectric unit, the first connecting sheet, the second piezoelectric unit, the middle beam and the first pre-tightening bolt form a first piezoelectric transducer, and the rear beam, the third piezoelectric unit, the second connecting sheet, the fourth piezoelectric unit, the middle beam and the second pre-tightening bolt form a second piezoelectric transducer;

if the materials are needed to be transported from the first piezoelectric transducer to the second piezoelectric transducer, applying a sinusoidal signal U1 to the first piezoelectric transducer, applying a sinusoidal signal U2 to the second piezoelectric transducer, wherein the frequencies and the voltages of the U1 and the U2 are the same and have a phase difference of pi/4, exciting longitudinal vibration modes of the first piezoelectric transducer and the second piezoelectric transducer, and inducing a traveling wave mode of the middle beam by superposing longitudinal vibrations of the two phases with the phase difference of pi/4; under the traveling wave mode, the vibration mode of a single mass point on the middle beam is represented as elliptical motion, so that materials placed on the middle beam move towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point;

if the materials need to be transported reversely, the phase difference between U1 and U2 is adjusted to-pi/4;

if the feed chute and the backspacing chute need to be isolated, the feed chute is communicated with the discharge chute without driving the piezoelectric bimorph;

if the feeding groove and the discharging groove are required to be isolated, the feeding groove is communicated with the backspacing groove, and a preset direct current signal is input to the piezoelectric bimorph, so that the piezoelectric bimorph can be bent.

The invention also discloses a third in-plane traveling wave type linear feeding device which comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, first to fourth piezoelectric ceramic sheets, first to second pre-tightening bolts, a piezoelectric bimorph, first to third stoppers and M + N + P adjusting bolts, wherein M, N, P are all natural numbers more than or equal to 1;

the first pre-tightening bolt sequentially penetrates through the through holes in the front beam and the first connecting piece from the countersunk through hole of the front beam and then is in threaded connection with the threaded blind hole at one end of the middle beam, and the front beam, the first connecting piece and the middle beam are clamped and are coaxial; the second pre-tightening bolt sequentially penetrates through the through holes in the rear beam and the second connecting sheet from the countersunk through hole of the rear beam and then is in threaded connection with the threaded blind hole at the other end of the middle beam, and the rear beam, the second connecting sheet and the middle beam are clamped tightly to enable the rear beam and the middle beam to be coaxial;

the first piezoelectric ceramic pieces, the second piezoelectric ceramic pieces, the third piezoelectric ceramic pieces and the fourth piezoelectric ceramic pieces are of the same structure and are polarized along the thickness direction, wherein the first piezoelectric ceramic pieces and the second piezoelectric ceramic pieces are symmetrically pasted on two sides of the front beam, the third piezoelectric ceramic pieces and the fourth piezoelectric ceramic pieces are symmetrically pasted on two sides of the rear beam, and the first piezoelectric ceramic pieces and the third piezoelectric ceramic pieces are positioned on the same side;

the polarization directions of the first piezoelectric ceramic piece and the second piezoelectric ceramic piece are both inward or outward, and the polarization directions of the third piezoelectric ceramic piece and the fourth piezoelectric ceramic piece are both inward or outward;

the adjusting bolt comprises a nut and a stud;

one end of the piezoelectric bimorph is fixedly connected with the third retaining piece, and the other end of the piezoelectric bimorph abuts against the second retaining piece and is used for blocking the feed chute and the backspacing chute under the non-driving state so as to communicate the feed chute with the discharge chute, and blocking the feed chute and the discharge chute under the driving state so as to communicate the feed chute with the backspacing chute.

The invention also discloses a working method of the second in-plane traveling wave type linear feeding device, which comprises the following steps:

the front beam, the first connecting piece, the middle beam, the first pre-tightening screw, the first piezoelectric ceramic piece and the second piezoelectric ceramic piece bolt form a first piezoelectric transducer, and the rear beam, the second connecting piece, the middle beam, the second pre-tightening screw, the third piezoelectric ceramic piece and the fourth piezoelectric ceramic piece form a second piezoelectric transducer;

if the required material is transported to the second piezoelectric transducer by the first piezoelectric transducer, a sinusoidal signal U1 is applied to the first piezoelectric transducer, a sinusoidal signal U2 is applied to the second piezoelectric transducer, the frequencies and the voltages of the U1 and the U2 are the same and have a phase difference of pi/4, longitudinal vibration modes of the first piezoelectric transducer and the second piezoelectric transducer are excited, and longitudinal vibration superposition of the two phases with the phase difference of pi/4 induces a traveling wave mode of the middle beam; under the traveling wave mode, the vibration mode of a single mass point on the middle beam is represented as elliptical motion, so that materials placed on the middle beam move towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point;

if the feeding groove and the backspacing groove need to be isolated, the feeding groove is communicated with the discharging groove, and the piezoelectric bimorph is not driven;

The invention also discloses a third in-plane traveling wave type linear feeding device which comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a damping block, a middle beam, a first piezoelectric unit, a second piezoelectric unit, a first pretightening bolt, a second pretightening bolt, a piezoelectric bimorph, a first blocking piece, a second pretightening bolt, a third blocking piece and M + N + P adjusting bolts, wherein M, N, P are all natural numbers which are more than or equal to 1;

the front beam is a cuboid with the same cross section as the cross section of the middle beam, and a countersunk through hole is formed in the center of one end face; the damping block is made of damping materials and is provided with a countersunk through hole;

the first piezoelectric unit, the second piezoelectric unit and the third piezoelectric unit have the same structure and comprise Q piezoelectric ceramic pieces, wherein Q is a natural number more than or equal to 1; the cross sections of the piezoelectric ceramic piece and the middle beam are the same in shape, and a through hole is formed in the center of the piezoelectric ceramic piece and the middle beam; the Q piezoelectric ceramic pieces are sequentially stacked and are polarized along the thickness direction, and the polarization directions of the adjacent piezoelectric ceramic pieces are opposite;

the first pre-tightening bolt sequentially penetrates through the front beam, the first piezoelectric unit, the through hole in the first connecting sheet and the second piezoelectric unit from the countersunk head through hole of the front beam and is in threaded connection with the threaded blind hole at one end of the middle beam, the front beam, the first piezoelectric unit, the first connecting sheet, the second piezoelectric unit and the middle beam are clamped, and the front beam, the first piezoelectric unit, the second piezoelectric unit and the middle beam are coaxial; the second pre-tightening bolt sequentially penetrates through the damping block and the through hole in the second connecting sheet from the countersunk through hole of the damping block and then is in threaded connection with the threaded blind hole at the other end of the middle beam, so that the damping block, the second connecting sheet and the middle beam are clamped tightly;

the polarization direction of the Q-th piezoelectric ceramic piece in the first piezoelectric unit is opposite to that of the 1 st piezoelectric ceramic piece in the second piezoelectric unit;

the adjusting bolt comprises a nut and a stud;

the M + N + P adjusting bolts penetrate through the M + N + P adjusting grooves in a one-to-one corresponding mode and are in one-to-one corresponding threaded connection with the M + N + P positioning threaded blind holes, the first blocking piece, the second blocking piece and the third blocking piece are fixed on the middle beam, a feeding groove is formed between the first blocking piece and the second blocking piece, a discharging groove is formed between the first blocking piece and the third blocking piece, and a returning groove is formed between the second blocking piece and the third blocking piece; an included angle between the backspacing groove and the discharge groove is an acute angle; the feeding groove is positioned between the front beam and the discharge groove;

The invention also discloses a working method of the third in-plane traveling wave type linear feeding device, which comprises the following steps:

the front beam, the first connecting piece, the middle beam, the first pre-tightening screw, the first piezoelectric unit and the second piezoelectric unit form a piezoelectric transducer; if the materials need to be conveyed from the feeding groove to the discharging groove or the backspacing groove, a sinusoidal signal with preset frequency is applied to the piezoelectric transducer, the longitudinal vibration mode of the piezoelectric transducer is excited, vibration is transmitted from the piezoelectric transducer to the damping material and is absorbed by the damping material, and the traveling wave mode of the middle beam is induced; under the traveling wave mode, the vibration mode of a single mass point on the center sill is represented as elliptical motion, so that materials placed on the center sill move towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point;

Compared with the prior art, the invention adopting the technical scheme has the following technical effects:

1. the piezoelectric transducer is adopted to excite the in-plane traveling wave mode of the middle beam, so that the material transportation is driven, and the piezoelectric transducer has the advantages of simple structure, easiness in control and low cost;

2. the in-plane traveling wave mode driving is adopted, and compared with an out-of-plane vibration mode and an inertia driving mode, the material can be transported more stably;

3. the propagation direction of the traveling wave mode can be changed by changing the phase difference of the two-phase excitation signals, so that the materials are propagated in the opposite direction, and compared with a linear type feeding device which is arranged in multiple rows and realizes bidirectional movement, the structure is simplified.

Drawings

Fig. 1 is a schematic structural view of a first in-plane traveling wave type linear feeding device according to the present invention;

FIG. 2 is a schematic view showing polarization directions of a first piezoelectric unit and a second piezoelectric unit according to the present invention;

fig. 3 is a schematic simulation diagram of a traveling wave mode of a first in-plane traveling wave type linear feeding device according to the present invention;

FIG. 4 is a schematic diagram illustrating a comparison between the non-driven state and the driven state of a piezoelectric bimorph of the first in-plane traveling wave type linear feeding device according to the present invention;

fig. 5 is a schematic structural view of a second in-plane traveling wave type linear feeder of the present invention;

fig. 6 is a schematic structural view of a third in-plane traveling wave type linear feeder according to the present invention.

In the figure, 1-a base, 2-a first connecting sheet, 3-a second connecting sheet, 4-a pre-tightening bolt, 5-a front beam, 6-a rear beam, 7-a first piezoelectric unit, 8-a second piezoelectric unit, 9-a third piezoelectric unit, 10-a fourth piezoelectric unit, 11-a middle beam, 12-a first stopper, 13-a second stopper, 14-a third stopper, 15-an adjusting bolt and 16-a piezoelectric bimorph.

Detailed Description

The technical scheme of the invention is further explained in detail by combining the attached drawings:

the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements, components and/or sections, these elements, components and/or sections should not be limited by these terms. These terms are only used to distinguish one element, component, and/or section from another. Thus, a first element, component, and/or section discussed below could be termed a second element, component, or section without departing from the teachings of the present invention.

The invention provides an in-plane traveling wave type linear feeding device and a working method thereof, aiming at improving the conveying efficiency of a piezoelectric vibration feeder, simplifying the structure of the device, improving the conveying stability and realizing the bidirectional conveying of materials. The device adopts the drive of in-plane traveling wave mode, compares in off-plane vibration mode and inertial drive mode, has reduced the vibration of vertical direction, has improved transportation stability. Meanwhile, the traveling wave propagation direction can be changed by changing the phase difference, so that the reverse transportation of the materials is realized.

As shown in fig. 1, the invention discloses an in-plane traveling wave type linear feeding device, which comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, first to fourth piezoelectric units, first to second pre-tightening bolts, a piezoelectric bimorph, first to third stoppers, and M + N + P adjusting bolts, wherein M, N, P are natural numbers more than or equal to 1;

the first piezoelectric unit, the second piezoelectric unit, the third piezoelectric unit and the fourth piezoelectric unit have the same structure and comprise Q piezoelectric ceramic pieces, and Q is a natural number more than or equal to 1; the piezoelectric ceramic piece and the middle beam have the same cross section shape, and a through hole is formed in the center; the Q piezoelectric ceramic pieces are sequentially stacked and are polarized along the thickness direction, and the polarization directions of the adjacent piezoelectric ceramic pieces are opposite;

the first pre-tightening bolt sequentially penetrates through the front beam, the first piezoelectric unit, the through hole in the first connecting sheet and the second piezoelectric unit from the countersunk head through hole of the front beam and is in threaded connection with the threaded blind hole at one end of the middle beam, the front beam, the first piezoelectric unit, the first connecting sheet, the second piezoelectric unit and the middle beam are clamped, and the front beam, the first piezoelectric unit, the second piezoelectric unit and the middle beam are coaxial; the second pre-tightening bolt sequentially penetrates through the through holes in the rear beam, the third piezoelectric unit, the second connecting sheet and the fourth piezoelectric unit from the countersunk head through hole of the rear beam and is connected with the threaded blind hole at the other end of the middle beam in a threaded manner, the rear beam, the third piezoelectric unit, the second connecting sheet, the fourth piezoelectric unit and the middle beam are clamped, and the rear beam, the third piezoelectric unit, the fourth piezoelectric unit and the middle beam are coaxial;

as shown in fig. 2, the polarization direction of the Q-th piezoelectric ceramic piece in the first piezoelectric unit is opposite to the polarization direction of the 1 st piezoelectric ceramic piece in the second piezoelectric unit, and the polarization direction of the Q-th piezoelectric ceramic piece in the third piezoelectric unit is opposite to the polarization direction of the 1 st piezoelectric ceramic piece in the fourth piezoelectric unit;

the adjusting bolt comprises a nut and a stud;

if the materials are needed to be transported from the first piezoelectric transducer to the second piezoelectric transducer, applying a sinusoidal signal U1 to the first piezoelectric transducer, applying a sinusoidal signal U2 to the second piezoelectric transducer, wherein the frequencies and the voltages of the U1 and the U2 are the same and have a phase difference of pi/4, exciting longitudinal vibration modes of the first piezoelectric transducer and the second piezoelectric transducer, and inducing a traveling wave mode of the middle beam by superposing longitudinal vibrations of the two phases with the phase difference of pi/4; in the traveling wave mode, the vibration mode of a single mass point on the center sill is represented as elliptical motion, so that the material placed on the center sill moves towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point, as shown in fig. 3;

if the feed groove and the discharge groove are required to be isolated, the feed groove is communicated with the backspacing groove, and a preset direct current signal is input to the piezoelectric bimorph, so that the piezoelectric bimorph can be bent, as shown in fig. 4.

As shown in fig. 5, the invention also discloses a third in-plane traveling wave type linear feeding device, which comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, first to fourth piezoelectric ceramic sheets, first to second pre-tightening bolts, a piezoelectric bimorph, first to third stoppers, and M + N + P adjusting bolts, wherein M, N, P are all natural numbers greater than or equal to 1;

the first connecting piece and the second connecting piece are of the same structure, are of rectangular sheet structures and are vertically arranged, the lower ends of the first connecting piece and the second connecting piece are fixedly connected with the base, and the upper ends of the first connecting piece and the second connecting piece are provided with through holes;

the polarization directions of the first piezoelectric ceramic piece and the second piezoelectric ceramic piece are inward or outward, and the polarization directions of the third piezoelectric ceramic piece and the fourth piezoelectric ceramic piece are inward or outward;

the adjusting bolt comprises a nut and a stud;

if the feed chute and the discharge chute are required to be isolated, the feed chute is communicated with the backspacing chute, and a preset direct current signal is input to the piezoelectric bimorph, so that the piezoelectric bimorph can be bent.

As shown in fig. 6, the invention also discloses a third in-plane traveling wave type linear feeding device, which comprises a base, a first connecting sheet, a second connecting sheet, a front beam, a damping block, a middle beam, first to second piezoelectric units, first to second pre-tightening bolts, a piezoelectric bimorph, first to third stoppers, and M + N + P adjusting bolts, wherein M, N, P are all natural numbers greater than or equal to 1;

the adjusting bolt comprises a nut and a stud;

the upper surfaces of the first blocking piece, the second blocking piece and the third blocking piece are respectively provided with M, N and P adjusting grooves, the adjusting grooves are strip-shaped grooves perpendicular to the middle beam, strip-shaped through grooves perpendicular to the middle beam are formed in the adjusting grooves, the width of each adjusting groove is larger than the diameter of a nut of the adjusting bolt, and the width of each strip-shaped through groove is smaller than the diameter of the nut of the adjusting bolt and larger than the diameter of a stud of the adjusting bolt;

m + N + P positioning threaded blind holes which correspond to M adjusting grooves in the first stopper, N adjusting grooves in the second stopper and P adjusting grooves in the third stopper one by one are formed in the upper surface of the middle beam;

the M + N + P adjusting bolts penetrate through the M + N + P adjusting grooves in a one-to-one corresponding mode and are in threaded connection with the M + N + P positioning threaded blind holes in a one-to-one corresponding mode, the first blocking piece, the second blocking piece and the third blocking piece are fixed on the middle beam, a feeding groove is formed between the first blocking piece and the second blocking piece, a discharging groove is formed between the first blocking piece and the third blocking piece, and a returning groove is formed between the second blocking piece and the third blocking piece; an included angle between the backspacing groove and the discharge groove is an acute angle; the feeding groove is positioned between the front beam and the discharge groove;

the front beam, the first connecting piece, the middle beam, the first pre-tightening screw, the first piezoelectric unit and the second piezoelectric unit form a piezoelectric transducer; if the materials are required to be conveyed from the feeding groove to the discharging groove or the backspacing groove, a sinusoidal signal with preset frequency is applied to the piezoelectric transducer, a longitudinal vibration mode of the piezoelectric transducer is excited, vibration is transmitted from the piezoelectric transducer to the damping material and is absorbed by the damping material, and a traveling wave mode of the middle beam is induced; under the traveling wave mode, the vibration mode of a single mass point on the middle beam is represented as elliptical motion, so that materials placed on the middle beam move towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point;

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An in-plane traveling wave type linear feeding device is characterized by comprising a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, a first piezoelectric unit, a second piezoelectric unit, a third piezoelectric unit, a fourth piezoelectric unit, a first pretightening bolt, a second pretightening bolt, a piezoelectric bimorph, a first blocking piece, a second pretightening bolt, a third blocking piece and M + N + P adjusting bolts, wherein M, N, P are natural numbers which are more than or equal to 1;

the front beam and the rear beam are of the same structure and are cuboids with the same cross section as that of the middle beam, and the center of one end face is provided with a countersunk through hole;

the first piezoelectric unit, the second piezoelectric unit, the third piezoelectric unit and the fourth piezoelectric unit have the same structure and comprise Q piezoelectric ceramic pieces, and Q is a natural number more than or equal to 1; the cross sections of the piezoelectric ceramic piece and the middle beam are the same in shape, and a through hole is formed in the center of the piezoelectric ceramic piece and the middle beam; the Q piezoelectric ceramic pieces are sequentially stacked and are polarized along the thickness direction, and the polarization directions of the adjacent piezoelectric ceramic pieces are opposite;

the adjusting bolt comprises a nut and a stud;

2. The in-plane traveling wave type linear feeder according to claim 1, wherein Q is 2.

3. The operating method of an in-plane traveling wave type linear feeder according to claim 1, comprising the steps of:

4. An in-plane traveling wave type linear feeding device is characterized by comprising a base, a first connecting sheet, a second connecting sheet, a front beam, a rear beam, a middle beam, first to fourth piezoelectric ceramic sheets, first to second pre-tightening bolts, a piezoelectric bimorph, first to third stoppers and M + N + P adjusting bolts, wherein M, N, P are natural numbers which are more than or equal to 1;

the first pre-tightening bolt sequentially penetrates through the through holes in the front beam and the first connecting piece from the countersunk through hole of the front beam and then is in threaded connection with the threaded blind hole at one end of the middle beam, so that the front beam, the first connecting piece and the middle beam are clamped and the front beam and the middle beam are coaxial; the second pre-tightening bolt sequentially penetrates through the through holes in the rear beam and the second connecting sheet from the countersunk through hole of the rear beam and then is in threaded connection with the threaded blind hole at the other end of the middle beam, and the rear beam, the second connecting sheet and the middle beam are clamped tightly to enable the rear beam and the middle beam to be coaxial;

the first piezoelectric ceramic pieces, the second piezoelectric ceramic pieces, the third piezoelectric ceramic pieces and the fourth piezoelectric ceramic pieces are of the same structure and are polarized along the thickness direction, wherein the first piezoelectric ceramic pieces and the second piezoelectric ceramic pieces are symmetrically adhered to two sides of the front beam, the third piezoelectric ceramic pieces and the fourth piezoelectric ceramic pieces are symmetrically adhered to two sides of the rear beam, and the first piezoelectric ceramic pieces and the third piezoelectric ceramic pieces are positioned on the same side;

the adjusting bolt comprises a nut and a stud;

5. The operating method of an in-plane traveling wave type linear feeder according to claim 4, comprising the steps of:

6. An in-plane traveling wave type linear feeding device is characterized by comprising a base, a first connecting sheet, a second connecting sheet, a front beam, a damping block, a middle beam, a first piezoelectric unit, a second piezoelectric unit, a first pretightening bolt, a second pretightening bolt, a piezoelectric bimorph, a first blocking piece, a second pretightening bolt, a third blocking piece and M + N + P adjusting bolts, wherein M, N, P are natural numbers which are more than or equal to 1;

the first piezoelectric unit, the second piezoelectric unit and the third piezoelectric unit have the same structure and comprise Q piezoelectric ceramic pieces, wherein Q is a natural number more than or equal to 1; the cross sections of the piezoelectric ceramic piece and the middle beam are the same in shape, and a through hole is formed in the center of the piezoelectric ceramic piece and the middle beam; the Q piezoelectric ceramic pieces are sequentially stacked and polarized along the thickness direction, and the polarization directions of the adjacent piezoelectric ceramic pieces are opposite;

the adjusting bolt comprises a nut and a stud;

7. The operating method of an in-plane traveling wave type linear feeder according to claim 6, comprising the steps of:

the front beam, the first connecting piece, the middle beam, the first pre-tightening screw, the first piezoelectric unit and the second piezoelectric unit form a piezoelectric transducer; if the materials are required to be conveyed from the feeding groove to the discharging groove or the backspacing groove, a sinusoidal signal with preset frequency is applied to the piezoelectric transducer, a longitudinal vibration mode of the piezoelectric transducer is excited, vibration is transmitted from the piezoelectric transducer to the damping material and is absorbed by the damping material, and a traveling wave mode of the middle beam is induced; under the traveling wave mode, the vibration mode of a single mass point on the center sill is represented as elliptical motion, so that materials placed on the center sill move towards the traveling wave propagation direction under the driving of the friction force of the elliptical motion of each mass point;