A piezoelectrically excited injector

Abstract

This invention discloses a piezoelectrically excited injector, relating to the field of droplet generation devices, used to improve the uniformity of droplet size and the consistency of droplet ejection velocity when the liquid flow rate is large. The piezoelectrically excited injector includes an end cap assembly, a housing, a rectifier, a piezoelectric ceramic, an excitation plate, and an injection panel. The housing has a first end and a second end disposed opposite to each other, and a first cavity extending from the first end to the second end. The rectifier includes an isolation portion and a connecting portion connected to each other. The connecting portion divides the first cavity into an upper cavity and a lower cavity, and the connecting portion has multiple rectifier holes. The piezoelectric ceramic is located in the second cavity and has a third end and a fourth end disposed opposite to each other. The excitation plate includes a sealing portion and a pressing portion. The outer wall of the sealing portion mates with and is slidably connected to the inner wall of the isolation portion. The pressing portion has an inverted frustum structure, and the lower cavity has an inner wall that conforms to the inverted frustum structure. The injection panel has multiple injection holes.

Description

Technical Field

[0001] This invention relates to the field of droplet generation device technology, and more particularly to a piezoelectrically excited injector. Background Technology

[0002] The ejector used for droplet generation is a core component of droplet radiators and space additive manufacturing equipment. Due to the special characteristics of the space environment and engineering application requirements, the ejector needs to generate a large number of droplets with uniform size and consistent velocity under high flow conditions. Problems such as uneven droplet size and inconsistent ejection velocity can lead to a decrease in equipment performance and pose potential risks to space safety.

[0003] The prerequisite for piezoelectrically excited nozzles to form uniform droplets is that the piezoelectric excitation disturbance within the nozzle dominates, and the surface waves of the jet develop and break up into ordered droplets under the action of the applied excitation. In existing piezoelectrically excited nozzles, the flow rate is relatively small, the Reynolds number of the liquid flow is low, and the flow field is relatively stable, with the piezoelectric excitation disturbance dominating. However, when the flow rate of the piezoelectrically excited nozzle is large, the flow impact within the nozzle is strong, and the local Reynolds number is high, resulting in a large amount of disordered pulsation in the flow field. At this point, the excitation disturbance is overwhelmed, leading to uneven droplet size and inconsistent jet velocity. Summary of the Invention

[0004] The purpose of this invention is to provide a piezoelectrically excited injector for improving the uniformity of droplet size and the consistency of droplet ejection velocity when the liquid flow rate is large.

[0005] To achieve the above objectives, the present invention provides a piezoelectric excitation nozzle, which includes an end cap assembly, a housing, a rectifier, a piezoelectric ceramic, an excitation plate, and an injection panel. The housing has a first end and a second end disposed opposite to each other, and a first cavity extending from the first end to the second end. An inlet is provided on the housing, and the end cap assembly covers the first end. The rectifier includes an isolation portion and a connecting portion connected to each other. The connecting portion is connected to the housing, dividing the first cavity into an upper cavity and a lower cavity. Multiple rectifier holes are provided on the connecting portion, and the upper cavity communicates with the lower cavity through these holes. The isolation portion is located within the upper cavity and has a through second cavity, with the inlet communicating with the upper cavity. The piezoelectric ceramic is located within the second cavity and has a third end and a fourth end disposed opposite to each other. The third end is disposed on the end cap assembly. The excitation plate is disposed at the fourth end and includes a sealing portion and a pressing portion. The outer wall of the sealing portion engages with and is slidably connected to the inner wall of the isolation portion. The pressing part is located in the lower cavity and has an inverted frustum structure. The lower cavity has an inner wall that fits the inverted frustum structure. The injection panel is located at the second end of the housing and has multiple injection holes.

[0006] When adopting the above technical solution, the piezoelectric excitation nozzle provided by the present invention includes an end cap assembly, a housing, a rectifier, a piezoelectric ceramic, an excitation plate, and a spraying panel. The housing has a first cavity extending from a first end to a second end. The connection portion of the rectifier divides the first cavity into an upper cavity and a lower cavity. The upper cavity and the lower cavity are connected through a rectifier hole on the connection portion, and the liquid inlet is connected to the upper cavity. After the liquid is delivered from the liquid inlet to the upper cavity, it is sprayed onto the outer wall of the isolation portion. The liquid can be distributed circumferentially in the upper cavity along the isolation portion, and then the liquid enters the lower cavity through the rectifier hole on the connection portion. The rectifier can improve the uniformity of the liquid flow field distribution in the first cavity and reduce the influence of the liquid jet at the liquid inlet. The piezoelectric ceramic has a third end and a fourth end arranged opposite to each other. The excitation plate is disposed at the fourth end. Under the action of the piezoelectric ceramic, the excitation plate can move towards and away from the spraying panel. As the excitation plate moves closer to the injection panel, the liquid is forced out of the injection holes on the injection panel by the squeezing action of the excitation plate, the inner wall of the lower cavity, and the injection panel. As the excitation plate moves away from the injection panel, the squeezed liquid forms droplets. The pressing part is located in the lower cavity and has an inverted truncated cone structure. The lower cavity has an inner wall that matches the inverted truncated cone structure, meaning that the lower cavity has a progressively contracting structure. This reduces the vortex structure and flow instability of the liquid flow field, reduces the disordered pulsation of the liquid in the injector, and keeps the liquid flow field smooth. When the liquid flow rate is large, it improves the uniformity of droplet size and the consistency of droplet injection velocity. Attached Figure Description

[0007] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:

[0008] Figure 1 This is a schematic diagram of a piezoelectrically excited injector provided in an embodiment of the present invention;

[0009] Figure 2 A diagram showing the effect of droplets generated using the piezoelectrically excited injector provided in this embodiment of the invention;

[0010] Figure 3 A diagram showing the droplet effect generated using a piezoelectrically excited injector provided by existing technology.

[0011] Figure label:

[0012] 1—End cap assembly, 11—Cover plate, 12—Fixing bracket, 21—Upper housing,

[0013] 22—Lower shell, 23—First cavity, 231—Upper cavity, 232—Lower cavity, 24—Liquid inlet

[0014] 3—rectifier, 31—isolation section, 311—second cavity, 32—connection section, 321—rectifier hole,

[0015] 33—Connecting rod, 4—Piezoelectric ceramic, 5—Excitation plate, 51—Sealing part, 52—Pressing part

[0016] 6—Injection panel, 61—Injection hole, 7—First sealing ring, 8—Pressure test hole, 9—Second sealing ring. Detailed Implementation

[0017] To facilitate a clear description of the technical solutions of the embodiments of the present invention, the terms "first" and "second" are used in the embodiments of the present invention to distinguish identical or similar items with essentially the same function and effect. Those skilled in the art will understand that the terms "first" and "second" do not limit the quantity or execution order, and the terms "first" and "second" are not necessarily different.

[0018] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0019] It should be noted that in this invention, the terms "exemplary" or "for example" are used to indicate examples, illustrations, or descriptions. Any embodiment or design described as "exemplary" or "for example" in this invention should not be construed as being more preferred or advantageous than other embodiments or designs. Specifically, the use of terms such as "exemplary" or "for example" is intended to present the relevant concepts in a concrete manner.

[0020] In this invention, "at least one" refers to one or more, and "more than one" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A alone, A and B simultaneously, or B alone, where A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or plural items. For example, at least one of a, b, or c can represent: a, b, c, a combination of a and b, a combination of a and c, a combination of b and c, or a, b, and c, where a, b, and c can be single or multiple.

[0021] Droplet generators for outer space applications require injectors to produce a large number of uniformly sized and velocously aligned large droplets in a vacuum environment. It should be understood that the prerequisite for piezoelectrically excited injectors to form uniform droplets is that piezoelectric excitation disturbances within the injector dominate, and the surface waves of the jet develop and break up into ordered droplets under the influence of the applied excitation. Current piezoelectrically excited injectors have relatively small flow rates, low Reynolds numbers, and relatively stable flow fields, where piezoelectric excitation disturbances are dominant and no additional flow field stabilization measures are needed. Space-use piezoelectrically excited injectors require larger jet flow rates, stronger flow impacts within the injector, higher local Reynolds numbers, and larger flow field disorder pulsations. Current piezoelectrically excited injectors can cause the piezoelectric excitation disturbances to be overwhelmed by the flow field disorder, preventing the jet from breaking up into ordered droplets under the applied excitation. This results in non-uniform droplet sizes and inconsistent jet velocities, posing a potential threat to the safety of spacecraft.

[0022] In order to solve the technical problems existing in the prior art, such as Figure 1 As shown, this embodiment of the invention provides a piezoelectric excitation nozzle, which includes an end cap assembly 1, a housing, a rectifier 3, a piezoelectric ceramic 4, an excitation plate 5, and a nozzle panel 6. The housing has a first end and a second end disposed opposite to each other, and a first cavity 23 extending from the first end to the second end. An inlet 24 is provided on the housing, and the end cap assembly 1 covers the first end. The rectifier 3 includes an isolation portion 31 and a connecting portion 32 connected to each other. The connecting portion 32 is connected to the housing, dividing the first cavity 23 into an upper cavity 231 and a lower cavity 232. Multiple rectifier holes 321 are provided on the connecting portion 32, and the upper cavity 231 communicates with the lower cavity 232 through the rectifier holes 321. The isolation portion 31 is located within the upper cavity 231 and has a through second cavity 311, with the inlet 24 communicating with the upper cavity 231. The piezoelectric ceramic 4 is located within the second cavity 311. The piezoelectric ceramic 4 has a third end and a fourth end arranged opposite to each other, with the third end disposed on the end cap assembly 1. An excitation plate 5 is disposed at the fourth end. The excitation plate 5 includes a sealing part 51 and a pressing part 52. The outer wall of the sealing part 51 mates with and is slidably connected to the inner wall of the isolation part 31. The pressing part 52 is located within the lower cavity 232 and has an inverted frustum structure. The lower cavity 232 has an inner wall that conforms to the inverted frustum structure. A spray panel 6 is disposed at the second end of the housing, and the spray panel 6 has multiple spray holes 61.

[0023] With the above technical solution, the piezoelectric excitation injector provided in this embodiment of the invention includes an end cap assembly 1, a housing, a rectifier 3, a piezoelectric ceramic 4, an excitation plate 5, and an injection panel 6. The housing has a first cavity 23 extending from a first end to a second end. The connection portion 32 of the rectifier 3 divides the first cavity 23 into an upper cavity 231 and a lower cavity 232. The upper cavity 231 and the lower cavity 232 are connected through a rectifier hole 321 on the connection portion 32. The liquid inlet 24 is connected to the upper cavity 231. After the liquid is delivered from the liquid inlet 24 to the upper cavity 231, it is sprayed onto the outer wall of the isolation portion 31. The liquid can be distributed circumferentially within the upper cavity 231 along the isolation portion 31. Then, the liquid enters the lower cavity 232 through the rectifier hole 321 on the connection portion 32. The rectifier 3 improves the uniformity of the liquid flow field distribution within the first cavity 23, reduces the influence of the subsequent liquid jet at the inlet 24, weakens the impact of the liquid jet, and reduces the liquid flow velocity. The piezoelectric ceramic 4 has a third end and a fourth end positioned opposite each other. The excitation plate 5 is located at the fourth end. Under the action of the piezoelectric ceramic 4, the excitation plate 5 can move towards and away from the injection panel 6. When the excitation plate 5 moves towards the injection panel 6, the liquid is forced out of the injection hole 61 on the injection panel 6 by the squeezing action of the excitation plate 5, the inner wall of the lower cavity 232, and the injection panel 6. When the excitation plate 5 moves away from the injection panel 6, the squeezed liquid forms droplets. The pressing part 52 is located inside the lower cavity 232, and the pressing part 52 has an inverted truncated cone structure. The lower cavity 232 has an inner wall that fits the inverted truncated cone structure. In other words, the lower cavity 232 has a progressively contracting structure, which can reduce the vortex structure and flow instability of the liquid flow field, reduce the disordered pulsation of the liquid in the injector, keep the liquid flow field smooth, and improve the uniformity of droplet size and the consistency of droplet injection speed when the liquid flow rate is large.

[0024] It should be understood that, due to the inherent characteristics of the piezoelectric ceramic 4, it expands when energized and contracts when de-energized. Thus, the piezoelectric ceramic 4 in the energized state is longer than that in the de-energized state. The excitation plate 5 is located at the fourth end of the piezoelectric ceramic 4. The piezoelectric ceramic 4 performs this expansion and contraction motion as it switches between energized and de-energized states, thereby driving the excitation plate 5 to move closer to and further away from the injection panel 6. Specifically, the excitation frequency of the piezoelectric ceramic 4 is 1kHz to 10kHz, depending on the actual situation. The excitation plate 5 continuously reciprocates in the direction of approaching and moving away from the injection panel 6, thus continuously generating droplets. One reciprocating motion of the excitation plate 5 in the direction of approaching and moving away from the injection panel 6 generates one droplet. The number of droplets generated at one time is the same as the number of injection holes 61 provided on the injection panel 6. The diameter of the formed droplets is related to the diameter of the injection holes 61. The number of injection holes 61 provided on the injection panel 6 can be 4 to 23. For example, the number of injection holes 61 can be 4, 8, 10, 12, 16, 20, 23, etc., without specific limitation. Multiple injection holes 61 are evenly distributed on the injection panel 6 to improve the uniformity of droplet size and the consistency of droplet ejection velocity. The diameter of the injection holes 61 is 1 mm to 2 mm. For example, the diameter of the injection holes 61 can be 1 mm, 1.2 mm, 1.5 mm, 1.8 mm, 2 mm, etc., without specific limitation, depending on the actual situation. In actual cases, the liquid flow rate ejected from the injection holes 61 is 0.02 kg / s to 1 kg / s, and the ejection velocity of the liquid ejected from the injection holes 61 is 5 m / s to 30 m / s.

[0025] In one example, such as Figure 1 As shown, the end cap assembly 1 includes a cover plate 11 and a fixing bracket 12. The fixing bracket 12 has a through third cavity. The first end of the housing is fixedly mounted on the cover plate 11 by screws, and the cover plate 11 is fixedly mounted on the fixing bracket 12 by screws. The third end of the piezoelectric ceramic 4 passes through the third cavity and is fixedly connected to the fixing bracket 12 by screws. The outer wall of the piezoelectric ceramic 4 is sealed to the inner wall of the third cavity by a second sealing ring 9.

[0026] As an optional approach, such as Figure 1As shown, the isolation section 31 of the rectifier 3 can be a cylindrical structure, and the connecting section 32 can be an annular plate structure. The outer wall of the isolation section 31 near the end cap assembly 1 is sealed to the inner wall of the housing. The isolation section 31 has a through second cavity 311, which can be cylindrical. The sealing section 51 of the excitation plate 5 can be a cylindrical structure that cooperates with the second cavity 311. The outer wall of the sealing section 51 cooperates with the inner wall of the isolation section 31 and is slidably connected, so that the piezoelectric ceramic 4 is sealed in the second cavity 311, avoiding direct contact and impact between the piezoelectric ceramic 4 and the liquid, thus preventing damage to the piezoelectric ceramic 4. The pressing part 52 has an inverted frustum structure, and the lower cavity 232 has an inner wall that matches the inverted frustum structure. The end of the lower cavity 232 near the upper cavity 231 has a frustum structure. A "V"-shaped progressive contraction channel is formed between the pressing part 52 and the inner wall of the lower cavity 232. The outer wall of the pressing part 52 and the inner wall of the frustum structure of the lower cavity 232 cooperate to gradually reduce the cross-sectional area of ​​the lower cavity 232, thereby reducing the disordered disturbance caused by the impact of liquid flow, promoting a smooth liquid flow field, and avoiding instability caused by sudden contraction and expansion. The end of the lower cavity 232 away from the upper cavity 231 has a cylindrical structure. In addition, the pressing part 52 is set as a conical structure, which, compared with a cylindrical structure, can increase the squeezing area of ​​the excitation plate 5 on the fluid (the squeezing area of ​​the excitation plate 5 with a cylindrical structure is equal to the cross-sectional area of ​​the cylinder).

[0027] In actual operation, the rectifier 3 also includes a connecting rod 33. One end of the connecting rod 33 is connected to the pressing part 52, and the other end of the connecting rod 33 is threaded to the fourth end of the piezoelectric ceramic 4. The connecting rod 33 has an annular weight-reducing groove around its perimeter to reduce the weight of the rectifier 3 and lower the load on the piezoelectric ceramic 4.

[0028] In one possible implementation, the axes of the first cavity 23, the piezoelectric ceramic 4, and the rectifier 3 are collinear. This results in a more uniform distribution of the liquid flow field within the upper cavity 231 and the lower cavity 232, which is beneficial for improving the uniformity of the generated droplets.

[0029] As an alternative, multiple rectifying holes 321 are evenly distributed circumferentially along the rectifying member 3, and multiple rows of rectifying holes 321 are provided along the radial direction of the rectifying member 3. In this case, the liquid flow field is more uniformly distributed within the lower cavity 232, which is beneficial to improving the uniformity of the generated droplets. The number of rectifying holes 321 can be 8 to 36. For example, the number of rectifying holes 321 can be 10, 16, 20, 24, 30, 34, or 36, and no specific limitation is made here.

[0030] In some embodiments, the axis of the rectifier orifice 321 is inclined outward from the direction from the upper cavity 231 to the lower cavity 232. For example... Figure 1As shown, at this time, the liquid jet entering the lower cavity 232 from the upper cavity 231 can impact the inner wall of the lower cavity 232, causing the vortex structure generated by the jet to dissipate rapidly, forming a uniform flow field in the lower cavity 232 as soon as possible, and improving the uniformity of the generated droplets.

[0031] Specifically, the angle between the axis of the rectifier hole 321 and the plane containing the connecting portion 32 is 30°-60°. For example, the angle between the axis of the rectifier hole 321 and the plane containing the connecting portion 32 can be 30°, 35°, 40°, 45°, 50°, 60°, etc. In practice, the extension direction of the axis of the rectifier hole 321 can intersect with the axis of the rectifier 3. In this case, the angle between the axis of the rectifier hole 321 and the axis of the rectifier 3 is 30°-60°, causing all the rectifier holes 321 to be inclined towards the axis of the rectifier 3.

[0032] As an optional example, the diameter of the rectifier aperture 321 is 1.8mm-2mm. For example, the diameter of the rectifier aperture 321 can be 1.8mm, 1.9mm, 1.96mm, 2mm, etc.

[0033] In one possible implementation, the housing provided in this embodiment of the invention includes an upper housing 21 and a lower housing 22. The upper housing 21 has an upper cavity 231, and the lower housing 22 has a lower cavity 232. The edge of the connecting portion 32 is sealed between the upper housing 21 and the lower housing 22. Figure 1 As shown. This facilitates the installation of the rectifier 3 inside the housing and also facilitates the sealing between the connecting part 32 and the housing, preventing liquid from entering the lower cavity 232 from the edge of the connecting part 32 and disrupting the liquid flow field. In specific implementations, sealing rings are provided between the edge of the connecting part 32 and the upper housing 21, and between the edge of the connecting part 32 and the lower housing 22.

[0034] As an optional approach, the outer wall of the sealing part 51 has a circumferentially oriented groove, within which a first sealing ring 7 is disposed. This groove serves to seal the sealing part 51 and the isolation part 31, preventing liquid from flowing into the second cavity 311 between the sealing part 51 and the isolation part 31, thus avoiding damage to the piezoelectric ceramic 4 and shortening the service life of the piezoelectric excitation injector. The circumferentially oriented groove on the outer wall of the sealing part 51, with the first sealing ring 7 disposed within it, enhances the firmness of the first sealing ring 7 between the sealing part 51 and the isolation part 31, improving the sealing performance between the sealing part 51 and the isolation part 31 and strengthening the protection of the piezoelectric ceramic 4. It should be noted that in the embodiments provided by this invention, the sealing rings can all be O-rings.

[0035] In a specific implementation, a pressure measuring hole 8 communicating with the upper cavity 231 is also provided on the outer wall of the housing. The pressure measuring hole 8 is used to install a pressure sensor. The pressure sensor is used to measure the pressure of the liquid in the upper cavity 231 to avoid the liquid pressure being too high or too low, which would affect the uniformity of the droplet size and the consistency of the droplet ejection speed.

[0036] Based on research and experiments, the droplet formation effect using the piezoelectrically excited injector provided in this embodiment of the invention is shown in the following figure. Figure 2 As shown, from Figure 2 As can be seen, the droplet size is uniform and the droplet continuity is high. In contrast, the droplet effect produced by existing piezoelectrically excited injectors is as follows: Figure 3 As shown, from Figure 3 As can be seen, the droplet size is uneven and the droplet distribution is disordered.

[0037] In one example, to meet the injection requirement of a liquid flow rate of 1 kg / s ejected from the injection hole 61, two rings of inclined rectification holes 321 are designed on the connecting part 32 along the radial direction of the rectifying component 3. The angle between the axis of the rectification hole 321 and the plane where the connecting part 32 is located is set to 45°. The diameter of the rectification hole 321 is 2 mm, and the number of rectification holes 321 is 36, with 18 rectification holes 321 set in one ring. The injection panel 6 is designed with 16 injection holes 61 with a diameter of 2 mm. The injection velocity of the liquid ejected from the injection hole 61 is 20 m / s. The excitation frequency acting on the piezoelectric ceramic 4 is set to 2 kHz. At this time, the piezoelectric excitation injector can generate droplets with a diameter of approximately 3.9 mm and uniform distribution.

[0038] In another example, along the radial direction of the rectifier 3, two rings of inclined rectifier holes 321 are designed on the connecting part 32. The angle between the axis of the rectifier hole 321 and the plane where the connecting part 32 is located is set to 60°. The diameter of the rectifier hole 321 is 2mm, and the total number of rectifier holes 321 is 18. Nine rectifier holes 321 can be set in one ring. The jet velocity of the liquid ejected from the injection hole 61 is 20m / s. The injection panel 6 is designed with 14 injection holes 61 with a diameter of 1.5mm. The excitation frequency acting on the piezoelectric ceramic 4 is 2.6kHz. At this time, droplets of about 3mm and uniformly distributed can be formed downstream of the ejector.

[0039] In summary, this invention utilizes a "V"-shaped contraction rectification structure to reduce disordered pulsations during fluid flow and employs encapsulated piezoelectric ceramics 4 to achieve ordered disturbances, thereby improving the generation effect of large-flow, millimeter-sized droplets. The piezoelectrically excited injector provided in this embodiment overcomes the shortcomings of conventional piezoelectrically excited injectors in generating large droplets and controlling droplet size consistency under conditions of multiple injection holes 61 and high flow rates, thus improving the uniform droplet generation effect.

[0040] Although the invention has been described herein in conjunction with various embodiments, those skilled in the art will understand and implement other variations of the disclosed embodiments by reviewing the accompanying drawings, the disclosure, and the appended claims in carrying out the claimed invention. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude a plurality. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0041] Although the invention has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made therein without departing from the spirit and scope of the invention. Accordingly, this specification and drawings are merely exemplary descriptions of the invention as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of the invention. Clearly, those skilled in the art can make various alterations and modifications to the invention without departing from its spirit and scope. Thus, if such modifications and modifications of the invention fall within the scope of the claims and their equivalents, the invention is also intended to include such modifications and modifications.

Claims

1. A piezoelectrically actuated injector, comprising: End cap assembly; The housing has a first end and a second end disposed opposite to each other; the housing has a first cavity extending from the first end to the second end; a liquid inlet is provided on the housing; and an end cap assembly is provided on the first end. A rectifier includes an isolation section and a connecting section connected to each other; the connecting section is connected to the housing, dividing the first cavity into an upper cavity and a lower cavity; the connecting section has a plurality of rectifier holes, and the upper cavity communicates with the lower cavity through the rectifier holes; the isolation section is located in the upper cavity; the isolation section has a through second cavity; the liquid inlet communicates with the upper cavity; A piezoelectric ceramic is located within the second cavity; the piezoelectric ceramic has a third end and a fourth end disposed opposite to each other; the third end is disposed on the end cap assembly. Its characteristic is that it further includes: An excitation plate is disposed at the fourth end; the excitation plate includes a sealing part and a pressing part, the outer wall of the sealing part is engaged with and slidably connected to the inner wall of the isolation part; the pressing part is located in the lower cavity; the pressing part is an inverted frustum structure, the lower cavity has an inner wall that fits the inverted frustum structure, the end of the lower cavity near the upper cavity is a frustum structure, a "V"-shaped progressive contraction channel is formed between the pressing part and the inner wall of the lower cavity, and the outer wall of the pressing part engages with the inner wall of the frustum structure of the lower cavity to gradually reduce the cross-sectional area of ​​the lower cavity; A spraying panel is disposed at the second end of the housing, and the spraying panel has multiple spraying holes. The excitation plate completes one reciprocating motion in the direction of approaching and moving away from the spraying panel, which can generate one droplet. The number of droplets generated at one time is the same as the number of spraying holes on the spraying panel. The diameter of the formed droplet is related to the diameter of the spraying hole, and the diameter of the spraying hole is 1.5mm~2mm. The flow rate of the liquid sprayed from the spraying hole is 0.02kg / s~1kg / s. This overcomes the shortcomings of conventional piezoelectric excitation sprayers in terms of large droplet generation and droplet size consistency control under multiple spraying holes and high flow conditions, and improves the uniform droplet generation effect.

2. The piezoelectrically actuated injector according to claim 1, characterized in that, The axis of the first cavity, the axis of the piezoelectric ceramic, and the axis of the rectifier are collinear.

3. The piezoelectrically actuated injector according to claim 1, characterized in that, The plurality of rectifier holes are evenly distributed along the circumference of the rectifier.

4. The piezoelectrically actuated injector according to claim 3, characterized in that, Multiple rows of rectifier holes are provided along the radial direction of the rectifier.

5. The piezoelectrically actuated injector according to claim 1, characterized in that, The axis of the rectifier hole is inclined outward from the direction from the upper cavity to the lower cavity.

6. The piezoelectrically actuated injector according to claim 5, characterized in that, The angle between the axis of the rectifier hole and the plane where the connecting part is located is 30°-60°.

7. The piezoelectrically actuated injector according to any one of claims 1 to 6, characterized in that, The diameter of the rectifier hole is 1.5mm-2.5mm.

8. The piezoelectrically actuated injector according to claim 1, characterized in that, The housing includes an upper housing and a lower housing, the upper housing having an upper cavity and the lower housing having a lower cavity; the edge seal of the connecting portion is disposed between the upper housing and the lower housing.

9. The piezoelectrically actuated injector according to claim 1, characterized in that, The outer wall of the sealing part is provided with a circumferentially arranged groove, and a first sealing ring is provided in the groove to seal the sealing part and the isolation part.

10. The piezoelectrically actuated injector according to claim 1, characterized in that, A pressure measuring hole communicating with the upper cavity is provided on the outer wall of the housing, and the pressure measuring hole is used to install a pressure sensor.

Images