CN116116661A

CN116116661A - Piezoelectric injection valve and correction method thereof

Info

Publication number: CN116116661A
Application number: CN202310239865.2A
Authority: CN
Inventors: 俞林军; 夏志刚; 苏梦达; 李腾飞; 张成就
Original assignee: Hangzhou Changchuan Technology Co Ltd
Current assignee: Hangzhou Changchuan Technology Co Ltd
Priority date: 2023-03-07
Filing date: 2023-03-07
Publication date: 2023-05-16

Abstract

The invention relates to a piezoelectric injection valve and a correction method thereof. The correction method comprises the following steps: 1) Introducing liquid into a piezoelectric injection valve, so that the liquid drops from a nozzle of the piezoelectric injection valve; 2) The position of a piezoelectric actuator of the piezoelectric injection valve is adjusted, so that a firing pin of the piezoelectric injection valve is driven to move towards the nozzle until the liquid dropping frequency of the nozzle is reduced to a preset frequency. Therefore, whether the contact pressure between the firing pin and the nozzle is proper or not is judged by observing the dropping frequency of the nozzle, and accurate observation and statistics are facilitated due to the dropping frequency, so that excessive dependence on experience of operators is avoided, the correction accuracy and consistency are improved, and the stability of the dispensing quality of the piezoelectric injection valve is improved.

Description

Piezoelectric injection valve and correction method thereof

Technical Field

The invention relates to the technical field of dispensing, in particular to a piezoelectric injection valve and a correction method thereof.

Background

Along with the rapid development of the electronic industry, the requirements on electronic packaging are higher and higher, and the non-contact piezoelectric injection valve is widely applied to the field of electronic packaging by aiming at the high-requirement electronic packaging technology and having the advantages of high efficiency, high precision and the like. The main structure of the piezoelectric injection valve is composed of a main valve body, a flow passage component, a nozzle for injecting glue, a firing pin and the like, and the main principle is as follows: the main valve body is electrified, the deformation of the piezoelectric actuator is amplified through an internal amplifying structure and is transmitted to the firing pin, the firing pin and the nozzle are contacted in the flow passage assembly to form a containing cavity, and glue solution in the containing cavity is sprayed out through the high-speed reciprocating motion of the firing pin to strike the nozzle, so that dispensing is completed. Therefore, the contact pressure between the striker and the nozzle has a large influence on the dispensing effect, and in order to improve the uniformity of the dispensing quality, the contact pressure between the striker and the nozzle needs to be corrected.

However, in the prior art, when dispensing operation is performed, the nozzle is manually adjusted to move up and down, so that the contact pressure between the firing pin and the nozzle is adjusted, the difference of correction results is large seriously depending on experience of operators, namely, the contact pressure between the firing pin and the nozzle corrected each time is poor in consistency, and the dispensing quality is adversely affected.

Disclosure of Invention

Based on this, it is necessary to provide a piezoelectric injection valve and a correction method thereof that improve the above-mentioned drawbacks, in order to solve the problem that the correction process for the piezoelectric injection valve in the prior art relies heavily on the experience of the operator, and the correction result varies greatly, thereby adversely affecting the dispensing quality.

A method of calibrating a piezo-electric injection valve, comprising the steps of:

1) Introducing liquid into a piezoelectric injection valve, so that the liquid is dropped by a nozzle of the piezoelectric injection valve;

2) And adjusting the position of a piezoelectric actuator of the piezoelectric injection valve, so as to drive a firing pin of the piezoelectric injection valve to move towards the nozzle until the liquid dropping frequency of the nozzle is reduced to a preset frequency.

In one embodiment, step 2) is followed by step 3):

and stopping introducing the liquid into the piezoelectric injection valve, and adjusting the compression amount of the pre-tightening spring of the piezoelectric injection valve to a preset compression amount.

In one embodiment, step 4) is further included after step 3):

continuing to introduce the liquid into the piezoelectric injection valve, and observing the dropping frequency of the nozzle;

and if the liquid dropping frequency of the nozzle is larger than the preset frequency, the step 2) and the step 3) are circularly executed.

In one embodiment, step 5) is further included after step 4):

fine-tuning the position of the nozzle in a direction away from the firing pin, and observing the dropping frequency of the nozzle;

and if the liquid dropping frequency of the nozzle is the preset frequency, performing the steps 2) to 4) in a circulating way.

In one embodiment, in step 5), the position of the nozzle is fine-tuned by a distance of not more than 1mm.

In one embodiment, one end of a pipeline containing the liquid is connected to an inlet of the piezoelectric injection valve, the other end of the pipeline is communicated with an external air source, and the liquid in the pipeline is pressed into the piezoelectric injection valve by using air flow provided by the external air source.

A piezoelectric injection valve corrected using the correction method described in any of the embodiments above, comprising:

the driving mechanism comprises a valve body, and a piezoelectric actuating assembly and a firing pin which are all arranged in the valve body;

the nozzle mechanism is provided with a nozzle matched with the firing pin, and the piezoelectric actuating assembly is in transmission connection with the firing pin so as to drive the firing pin to move relative to the nozzle and extrude dispensing medium entering the nozzle to be sprayed out of the nozzle; a kind of electronic device with high-pressure air-conditioning system

The first adjusting mechanism is arranged on the valve body, is matched and connected with the piezoelectric actuating assembly and is used for adjusting the piezoelectric actuating assembly so that the piezoelectric actuating assembly drives the firing pin to adjust the position of the firing pin relative to the nozzle.

In one embodiment, the injection valve includes a second adjustment mechanism disposed on the valve body; the driving mechanism comprises a pre-tightening spring positioned in the valve body, and two opposite ends of the pre-tightening spring are respectively abutted against the piezoelectric actuation assembly and the second adjusting mechanism so as to provide a pre-tightening force for enabling the piezoelectric actuation assembly to have a movement trend away from the nozzle;

the second adjusting mechanism is used for adjusting the compression amount of the pre-tightening spring.

In one embodiment, the second adjusting mechanism comprises a wedge block and an adjusting piece, and the wedge block is movably arranged at one end of the pre-tightening spring far away from the piezoelectric actuating assembly; the adjusting piece is arranged on the valve body and is configured to operably drive the wedge block to move so that the wedge block compresses or releases the pre-tightening spring.

In one embodiment, the second adjusting mechanism further comprises an abutment seat movably connected to the valve body along the compression direction of the pre-tightening spring, and two opposite ends of the pre-tightening spring are respectively abutted against the piezoelectric actuating component and the abutment seat;

the valve body is provided with a third abutting part which is positioned at one side of the abutting seat away from the pre-tightening spring, the wedge block is arranged between the abutting seat and the third abutting part, and the wedge block is provided with a first surface abutting against the abutting seat and a second surface abutting against the third abutting part;

one of the first surface and the second surface is parallel to a dummy plane, the other of the first surface and the second surface is inclined with respect to the dummy plane, and the dummy plane is perpendicular to the compression direction of the pretension spring.

According to the piezoelectric injection valve and the correction method thereof, whether the contact pressure between the firing pin and the nozzle is proper or not is judged by observing the dropping frequency of the nozzle, and accurate observation and statistics are facilitated due to the dropping frequency, so that excessive dependence on experience of operators is avoided, the correction accuracy and consistency are improved, and the stability of the dispensing quality of the piezoelectric injection valve is improved.

Drawings

FIG. 1 is a schematic diagram of a piezojet valve according to an embodiment of the present invention;

FIG. 2 is a cross-sectional view of the piezo jet valve shown in FIG. 1;

FIG. 3 is a schematic illustration of the nozzle and striker engagement of the piezo jet valve of FIG. 1;

FIG. 4 is a schematic diagram of a second adjustment mechanism of the piezo jet valve shown in FIG. 1;

fig. 5 is a flowchart of a method for calibrating a piezojet valve according to an embodiment of the present invention.

Detailed Description

In order that the above objects, features and advantages of the invention will be readily understood, a more particular description of the invention will be rendered by reference to the appended drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. The present invention may be embodied in many other forms than described herein and similarly modified by those skilled in the art without departing from the spirit of the invention, whereby the invention is not limited to the specific embodiments disclosed below.

In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings are merely for convenience in describing the present invention and simplifying the description, and do not indicate or imply that the device or element being referred to must have a specific orientation, be configured and operated in a specific orientation, and therefore should not be construed as limiting the present invention.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include at least one such feature. In the description of the present invention, the meaning of "plurality" means at least two, for example, two, three, etc., unless specifically defined otherwise.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; either directly or indirectly, through intermediaries, or both, may be in communication with each other or in interaction with each other, unless expressly defined otherwise. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

In the present invention, unless expressly stated or limited otherwise, a first feature "up" or "down" a second feature may be the first and second features in direct contact, or the first and second features in indirect contact via an intervening medium. Moreover, a first feature being "above," "over" and "on" a second feature may be a first feature being directly above or obliquely above the second feature, or simply indicating that the first feature is level higher than the second feature. The first feature being "under", "below" and "beneath" the second feature may be the first feature being directly under or obliquely below the second feature, or simply indicating that the first feature is less level than the second feature.

It will be understood that when an element is referred to as being "fixed" or "disposed" on another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like are used herein for illustrative purposes only and are not meant to be the only embodiment.

Referring to fig. 1 to 3, an embodiment of the present invention provides a piezoelectric injection valve, which includes a driving mechanism 10, a nozzle mechanism 20 and a first adjusting mechanism 30. The driving mechanism 10 includes a valve body 11, a piezoelectric actuator assembly 12 and a striker 125 both disposed in the valve body 11. The nozzle mechanism 20 has a nozzle 22 that mates with a striker 125. The piezoelectric actuating assembly 12 is in driving connection with the firing pin 125 to drive the firing pin 125 to move relative to the nozzle 22, and the dispensing medium extruded into the nozzle 22 is ejected from the nozzle 22, thereby dispensing. The first adjusting mechanism 30 is disposed on the valve body 11 and is cooperatively connected with the piezoelectric actuating assembly 12, and is used for adjusting the piezoelectric actuating assembly 12, so that the piezoelectric actuating assembly 12 drives the striker 125 to adjust the position relative to the nozzle 22, thereby adjusting the contact pressure between the striker 125 and the nozzle 22.

In particular, in the embodiment, the nozzle mechanism 20 further includes a runner base 21, the runner base 21 is fixedly connected to the valve body 11, the nozzle 22 is disposed on the runner base 21, the runner base 21 has a runner 23 that communicates with the nozzle 22, and an inlet of the runner 23 is provided with a luer connector 24 for connection with an external pipeline (not shown), so that the dispensing medium can enter the runner 23 through the external pipeline. The outlet of the runner 23 is communicated with the nozzle 22, so that the dispensing medium entering the runner 23 can enter the nozzle 22, and then dispensing is realized under the cooperation of the nozzle 22 and the firing pin 125.

Further, the nozzle 22 is screwed to the flow path seat 21, and the nozzle 22 can be moved toward or away from the striker 125 when the nozzle 22 is screwed.

In particular to the embodiment, the piezoelectric actuation assembly 12 includes a piezoelectric actuator 121 and an amplifying lever 123, and the drive mechanism 10 further includes a pretension spring 13 located within the valve body 11. The amplification lever 123 has a hinge portion a1, a first abutting portion a2, and a second abutting portion a3, and the hinge portion a1 is hinge-connected to the valve body 11, the first abutting portion a2 being located between the hinge portion a1 and the second abutting portion a3. The piezoelectric actuator 121 is movably provided to the valve body 11, one end of the piezoelectric actuator 121 abuts against the first adjusting mechanism 30, and the other end of the piezoelectric actuator 121 abuts against the first abutting portion a2 of the amplification lever 123. The striker 125 is movably provided in the valve body 11, and one end of the striker 125 is engaged with the nozzle 22, and the other end of the striker 125 is in contact with the second contact portion a3 of the amplification lever 123. The pretensioning spring 13 is fitted over the striker 125, and one end of the pretensioning spring 13 abuts against the second abutment portion a3 of the amplification lever 123, and the other end of the pretensioning spring 13 abuts against the valve body 11. In this way, when the dispensing operation is performed, the piezoelectric actuator 121 is energized and started, and generates up-and-down vibration, so that the amplifying lever 123 swings up-and-down under the combined action of the up-and-down vibration generated by the piezoelectric actuator 121 and the pre-tightening force provided by the pre-tightening spring 13, so as to drive the striker 125 to reciprocate up-and-down, so that the striker 125 continuously extrudes the injection medium to be injected from the nozzle 22, and dispensing is realized.

Further, a return spring for providing a return force urging the striker 125 to remain in abutment with the second abutment portion a3 of the amplification lever 123 is fitted to the outer side of the striker 125. Thus, when amplification lever 123 swings in a direction away from nozzle 22 (i.e., swings upward as shown in fig. 2) under the biasing force provided by biasing spring 13, striker 125 also follows amplification lever 123 away from nozzle 22 under the biasing force provided by the biasing spring. When the amplification lever 123 swings in a direction approaching the nozzle 22 (i.e., swings downward as shown in fig. 2) under the driving of the piezoelectric actuation assembly 12, the amplification lever 123 drives the striker 125 to move approaching the nozzle 22 (i.e., moves downward as shown in fig. 2).

Further, the first adjusting mechanism 30 includes an adjusting screw 31, the adjusting screw 31 is screwed to the valve body 11, and one end of the adjusting screw 31 abuts against an end of the piezoelectric actuator 121 remote from the amplifying lever 123. In this way, when the contact pressure between the striker 125 and the nozzle 22 is corrected, the adjusting screw 31 can be screwed forward or backward to drive the piezoelectric actuator 121 to move to adjust the position thereof, so that the piezoelectric actuator 121 can drive the amplifying lever 123 to swing, and the amplifying lever 123 can drive the striker 125 to move close to or far from the nozzle 22, thereby achieving the purpose of adjusting the contact pressure between the striker 125 and the nozzle 22.

In particular to the embodiment, the piezoelectric injection valve further includes a second adjustment mechanism 40 provided to the valve body 11, and an end of the pretension spring 13 facing away from the second abutment a3 abuts against the second adjustment mechanism 40. The pretension spring 13 serves to provide a pretension force that causes the amplification lever 123 to have a movement tendency away from the nozzle 22. As shown in fig. 2, the pretension spring 13 applies an upward pretension force to the second abutment portion a3 of the amplification lever 123. The second adjusting mechanism 40 is used to adjust the compression amount of the pretension spring 13, thereby adjusting the magnitude of the pretension force applied to the amplification lever 123.

It should be noted that, the pre-tightening force provided by the pre-tightening spring 13 is critical to the stability of the piezoelectric actuator 121 driving the striker 125 to reciprocate up and down, so in order to ensure the dispensing quality, the pre-tightening force provided by the pre-tightening spring 13 needs to be within a design range (designed according to the specific valve specification) and cannot be too large or too small. In this embodiment, after the contact pressure between the striker 125 and the nozzle 22 is corrected by the first adjusting mechanism 30, the position of the amplifying lever 123 is changed, so that the compression amount of the pre-tightening spring 13 is also changed (i.e., the pre-tightening force provided by the pre-tightening spring 13 is also changed), and at this time, the compression amount of the pre-tightening spring 13 can be adjusted by the second adjusting mechanism 40, so that the compression amount of the pre-tightening spring 13 meets the requirement, and the pre-tightening force provided by the pre-tightening spring 13 is ensured to be within the design range.

Referring to fig. 4, further, the second adjusting mechanism 40 includes a wedge 42 and an adjusting member 41. The wedge block 42 is movably disposed at an end of the pretension spring 13 away from the second abutment portion a3. The adjusting member 41 is disposed on the valve body 11 and is configured to operatively drive the wedge block 42 to move, so that the wedge block 42 compresses or releases the pre-tightening spring 13, thereby adjusting the compression amount of the pre-tightening spring 13 and thus the pre-tightening force provided by the pre-tightening spring 13. Optionally, the adjusting member 41 is screwed to the valve body 11, and one end of the adjusting member 41 is connected to the wedge block 42, so that the wedge block 42 can be driven to move and compress or release the pretensioning spring 13 by screwing the adjusting member 41 in a forward direction or a reverse direction, that is, the adjustment of the compression amount of the pretensioning spring 13 is achieved.

Further, the second adjusting mechanism 40 further includes an abutment 43, and the abutment 43 is movably disposed in the valve body 11 along the compression direction of the pretension spring 13. Opposite ends of the pre-tightening spring 13 are respectively abutted against the piezoelectric actuating assembly 12 and the abutment seat 43. The valve body 11 has a third abutment a3 on the side of the abutment 43 facing away from the pretensioning spring 13. The wedge block 42 is disposed between the abutment 43 and the third abutment a3, and the wedge block 42 has a first surface b1 abutting against the abutment 43 and a second surface b2 abutting against the third abutment a3. One of the first surface b1 and the second surface b2 is parallel to a dummy plane, the other of which is inclined with respect to the dummy plane, the dummy plane being perpendicular to the compression direction of the pretensioning spring 13.

In particular, in the embodiment shown in fig. 2 or 4, the dummy plane is a horizontal plane, the first surface b1 is parallel to the dummy plane (i.e. perpendicular to the compression direction of the pretensioning spring 13), and the second surface b2 is inclined with respect to the dummy plane. Thus, when the adjusting member 41 is screwed and the wedge block 42 is driven to move rightward, the wedge block 42 presses the abutment seat 43 to move upward under the guiding action of the second surface b2, thereby increasing the compression amount of the pretension spring 13. When the adjusting member 41 is screwed and the wedge block 42 is driven to move leftward, the wedge block 42 is displaced downward by the guide of the second surface b2, so that the abutment seat 43 moves downward under the abutment of the pretensioning spring 13, thereby realizing a reduction in the compression amount of the pretensioning spring 13.

The operation of the first adjustment mechanism 30 and the second adjustment mechanism 40 will be described below with reference to fig. 2:

when the striker 125 needs to be adjusted to approach the nozzle 22, the adjusting screw 31 is screwed to drive the piezoelectric actuator 121 to move downwards, so that the piezoelectric actuator 121 drives the amplifying lever 123 to rotate anticlockwise against the pretightening force of the pretightening spring 13, and the striker 125 is driven to move downwards to approach the nozzle 22.

When it is desired to adjust the striker 125 away from the nozzle 22, the adjusting screw 31 is screwed to drive the piezoelectric actuator 121 to move upward, so that the amplification lever 123 rotates clockwise under the biasing force provided by the biasing spring 13, and the striker 125 moves upward away from the nozzle 22 under the biasing force of the return spring.

When the compression amount of the pre-tightening spring 13 needs to be increased (i.e. when the pre-tightening force provided by the pre-tightening spring 13 is increased), the adjusting piece 41 is screwed so as to drive the wedge block 42 to move rightward, so that the wedge block 42 presses the abutting seat 43 to move upward, and the pre-tightening spring 13 is compressed, i.e. the compression amount of the pre-tightening spring 13 is increased.

When the compression amount of the pre-tightening spring 13 needs to be reduced (i.e., the pre-tightening force provided by the pre-tightening spring 13 is reduced), the adjusting member 41 is screwed so as to drive the wedge block 42 to move leftwards, so that the pre-tightening spring 13 presses the abutment seat 43 to move downwards, and the compression amount of the pre-tightening spring 13 is reduced.

Referring to fig. 5, based on the piezoelectric injection valve, the invention further provides a method for calibrating the piezoelectric injection valve, which comprises the following steps:

and S10, introducing liquid with better flow into the flow channel 23 of the piezoelectric injection valve, so that the liquid enters the nozzle 22 from the flow channel 23 and drops outwards from the nozzle 22. Specifically, the liquid is contained in a tube, and one end of the tube is connected to the inlet of the piezo jet valve (i.e., luer fitting 24 described above), and the other end of the tube is in communication with an external air source. The liquid in the line is forced into the flow channel 23 of the piezo jet valve by an air flow provided by an external air source and drops from the nozzle 22. Thus, when the external air source is turned on, the air pressure provided by the external air source presses the liquid in the pipeline into the flow passage 23 of the piezoelectric jetting valve. When the external air supply is turned off, the liquid in the line stops entering the flow channel 23 of the piezo jet valve.

And S20, adjusting the position of a piezoelectric actuator 121 of the piezoelectric injection valve, so as to drive a firing pin 125 of the piezoelectric injection valve to move towards the nozzle 22 until the liquid dropping frequency of the nozzle 22 is reduced to a preset frequency. Specifically, in order to ensure that the striker 125 and the nozzle 22 are separated from each other at the start of adjusting the position of the striker 125, it is necessary that the piezoelectric actuator 121 is energized and the adjustment screw 31 is screwed to move the piezoelectric actuator 121 upward, so that the striker 125 is moved upward by the return spring to separate the striker 125 from the nozzle 22. Then, the adjustment screw 31 is reversely screwed to drive the piezoelectric actuator 121 to move downward, so that the striker 125 comes closer to the nozzle 22. During the movement of the adjustment plunger 125 gradually closer to the nozzle 22, the change in the drip frequency of the nozzle 22 is observed until the drip frequency of the nozzle 22 decreases to a preset frequency, and the screwing of the adjustment screw 31 is stopped.

In this way, whether the contact pressure between the firing pin 125 and the nozzle 22 is proper is judged by observing the dropping frequency of the nozzle 22, and the accurate observation and statistics are convenient for the dropping frequency, so that the excessive dependence on the experience of operators is avoided, the correction accuracy and consistency are improved, and the stability of the dispensing quality of the piezoelectric injection valve is improved.

Alternatively, the preset frequency may be a specific value, for example, 0, and no droplet is dropped from the nozzle 22 when the droplet frequency of the nozzle 22 is 0. That is, in the process of adjusting the striker 125 to gradually approach the nozzle 22 in step S20, the screwing of the adjusting screw 31 is stopped when the nozzle 22 is not dropping. Of course, in other embodiments, the preset frequency may be a value slightly greater than 0, and may be set according to the fluidity of the liquid and the specification of the piezo jet valve, which is not limited herein.

Of course, in other embodiments, the preset frequency may be a frequency range (for example, a range slightly greater than 0), which may be set according to the fluidity of the liquid and the specification of the piezo jet valve, which is not limited herein.

In particular embodiments, the liquid in the flow passage 23 leading into the piezo jet valve may be a volatile liquid, such as alcohol. In this way, by utilizing the characteristic that the liquid is volatile, the liquid can be prevented from remaining in the flow channel 23 and the nozzle 22 of the piezoelectric injection valve, namely, the glue dispensing medium entering the piezoelectric injection valve is prevented from being mixed with the remaining liquid when the glue dispensing operation is carried out later, so that the performance of the glue dispensing medium is prevented from being influenced.

The preload applied by the preload spring 13 to the amplification lever 123 affects the stability of the up-and-down reciprocating motion of the striker 125, and thus it is necessary to ensure that the preload applied by the preload spring 13 to the amplification lever 123 satisfies the design requirements. However, when the contact pressure of the striker 125 with the nozzle 22 is adjusted in step S20, the compression amount of the pretensioning spring 13 tends to be changed, resulting in an increase or decrease in the pretensioning force of the pretensioning spring 13 applied to the amplification lever 123, thereby affecting the dispensing quality. To overcome the above-mentioned drawbacks, in one embodiment, step S30 is further included after step S20:

the liquid supply to the flow passage 23 of the piezo jet valve is stopped, and the compression amount of the pretensioning spring 13 of the piezo jet valve is adjusted to a preset compression amount.

In this way, after the position of the striker 125 is adjusted in place in step S20, the compression amount of the pre-tightening spring 13 is adjusted to the preset compression amount, so as to ensure that the pre-tightening force applied to the amplifying lever 123 by the pre-tightening spring 13 meets the design requirement, which is beneficial to improving the dispensing quality.

Further, step S20 specifically includes: the piezoelectric actuator 121 is de-energized and the external air supply is shut off, thereby stopping the liquid in the line from entering the flow passage 23 of the piezoelectric injector. Then, the length of the pre-tension spring 13 is measured by a measuring tool, thereby obtaining the compression amount of the pre-tension spring 13 at this time. The pretension spring 13 is then driven to extend or shorten by screwing the adjusting member 41 until the compression amount of the compression spring reaches a preset compression amount. Of course, the preset compression amount may be a specific value or a range, and is set according to the specification of the piezoelectric injection valve or the like, and is not limited herein.

In particular, in the embodiment, step S40 (i.e., a step of determining whether the contact pressure of the striker 125 with the nozzle 22 is small) is further included after step S30:

continuing to introduce liquid into the flow channel 23 of the piezoelectric injection valve, and observing the dropping frequency of the nozzle 22;

if the drop frequency of the nozzle 22 is greater than the preset frequency, it indicates that the contact pressure between the striker 125 and the nozzle 22 is smaller, and the contact pressure between the striker 125 and the nozzle 22 needs to be readjusted by performing the steps S20 and S30 in a circulating manner; if the frequency of the droplet of the nozzle 22 is maintained at the predetermined frequency, it indicates that the contact pressure between the plunger 125 and the nozzle 22 is not small. In this way, by again introducing liquid into the piezoelectric injection valve and judging whether the contact pressure between the plunger 125 and the nozzle 22 is small or not according to the liquid drop frequency of the nozzle 22, the accuracy of correcting the contact pressure between the plunger 125 and the nozzle 22 is further improved. The piezoelectric actuator 121 is re-energized when step S40 is performed.

In particular, in the embodiment, step S50 (i.e., a step of determining whether the contact pressure of the striker 125 with the nozzle 22 is large) is further included after step S40:

fine-tuning the position of the nozzle 22 in a direction away from the striker 125;

if the drop frequency of the nozzle 22 is the preset frequency, it indicates that the contact pressure between the striker 125 and the nozzle 22 is large, and the steps S20 to S40 need to be performed in a circulating manner. If the frequency of the droplet of the nozzle 22 is greater than the preset frequency, it indicates that the contact pressure between the striker 125 and the nozzle 22 is not large. In this way, by again introducing liquid into the piezoelectric injection valve and determining whether the contact pressure between the plunger 125 and the nozzle 22 is too high or not based on the frequency of the liquid droplets from the nozzle 22, the accuracy of the correction of the contact pressure between the plunger 125 and the nozzle 22 is further improved.

The adjustment of the position of the nozzle 22 in step S50 is not too large nor too small. The too large adjustment of the position of the nozzle 22 increases the drop frequency avoidance of the nozzle 22, and therefore the effect of judging whether the contact pressure of the striker 125 with the nozzle 22 is too large cannot be obtained. If the position of the nozzle 22 is adjusted too small, the drop frequency will not change even when the contact pressure between the striker 125 and the nozzle 22 is not too large, and therefore, the effect of determining whether the contact pressure between the striker 125 and the nozzle 22 is too large cannot be achieved. To overcome the above-described drawbacks, in some embodiments, the position of the nozzle 22 is fine-tuned by a distance of not more than 1mm in step S50, thereby ensuring that it is possible to accurately judge whether the contact pressure of the plunger 125 with the nozzle 22 is excessive or not by the liquid-dropping frequency of the nozzle 22.

After the position of the nozzle 22 is finely adjusted in step S50, the position of the nozzle 22 needs to be reset. For example, initially the nozzle 22 is in the limit position for tightening (i.e., the position closest to the striker 125). The nozzle 22 is unscrewed in step S50 such that the nozzle 22 moves no more than 1mm away from the striker 125 (i.e., the distance of fine adjustment is controlled by controlling the number of turns of unscrewing the nozzle 22). After determining whether the contact pressure of the nozzle 22 with the striker 125 is too great, it is necessary to screw the nozzle 22 to the limit position (i.e., reset).

The correction method of the piezoelectric injection valve has at least the following beneficial effects:

by observing the dropping frequency of the nozzle 22, the correction of the contact pressure between the firing pin 125 and the nozzle 22 is realized, the correction deviation of the contact pressure between the firing pin 125 and the nozzle 22 caused by the reasons of repeated correction of the same valve body, correction of different valve bodies, correction of different technicians and the like is reduced or eliminated, and the consistency of the dispensing performance of the piezoelectric injection valve is improved;

on the premise of correcting the contact pressure between the firing pin 125 and the nozzle 22, the compression amount of the pre-tightening spring 13 is corrected, so that the pre-tightening force of the pre-tightening spring 13 to the piezoelectric actuator 121 is ensured to meet the requirement, and the performance and the precision of the piezoelectric injection valve are ensured;

the contact pressure between the striker 125 and the nozzle 22 is regulated by the first regulating screw 31 of the first regulating mechanism 30, the compression amount of the pre-tightening spring 13 is regulated by the regulating member 41 of the second regulating mechanism 40, and the first regulating mechanism 30 and the second regulating mechanism 40 have simple structures, and the main structure of the piezoelectric injection valve is not changed, so that the influence on the performance of the piezoelectric injection valve is small, and the dispensing quality is further ensured.

The technical features of the above-described embodiments may be arbitrarily combined, and all possible combinations of the technical features in the above-described embodiments are not described for brevity of description, however, as long as there is no contradiction between the combinations of the technical features, they should be considered as the scope of the description.

The above examples illustrate only a few embodiments of the invention, which are described in detail and are not to be construed as limiting the scope of the invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention. Accordingly, the scope of protection of the present invention is to be determined by the appended claims.

Claims

1. A method of calibrating a piezo-electric injection valve, comprising the steps of:

1) Introducing a liquid into a piezo jet valve such that the liquid drips from a nozzle (22) of the piezo jet valve;

2) The position of a piezoelectric actuator (121) of the piezoelectric injection valve is adjusted so as to drive a firing pin (125) of the piezoelectric injection valve to move towards the nozzle (22) until the dropping frequency of the nozzle (22) is reduced to a preset frequency.

2. The method of calibrating a piezo-electric injection valve according to claim 1, further comprising step 3) after said step 2):

stopping the liquid from being introduced into the piezoelectric injection valve, and adjusting the compression amount of a pre-tightening spring (13) of the piezoelectric injection valve to a preset compression amount.

3. The method of calibrating a piezo-electric injection valve according to claim 2, further comprising step 4) after said step 3):

continuing to feed the liquid into the piezoelectric injection valve and observing the dropping frequency of the nozzle (22);

and if the dropping frequency of the nozzle (22) is larger than the preset frequency, the step 2) and the step 3) are circularly executed.

4. A method of calibrating a piezo-electric injection valve according to claim 3, further comprising step 5) after said step 4):

fine-tuning the position of the nozzle (22) in a direction away from the striker (125), and observing the frequency of dripping of the nozzle (22);

and if the dropping frequency of the nozzle (22) is the preset frequency, performing the steps 2) to 4) in a circulating way.

5. The method of calibrating a piezo jet valve according to claim 4, characterized in that in step 5) the position of the nozzle (22) is fine tuned by a distance not exceeding 1mm.

6. The method according to any one of claims 1 to 5, wherein one end of a pipe containing the liquid is connected to an inlet of the piezoelectric jetting valve, the other end of the pipe is communicated with an external air source, and the liquid in the pipe is pressed into the piezoelectric jetting valve by an air flow supplied from the external air source.

7. A piezoelectric injection valve corrected by the correction method according to any one of claims 1 to 6, characterized by comprising:

a driving mechanism (10) comprising a valve body (11), a piezoelectric actuation assembly (12) and a firing pin (125) both arranged in the valve body (11);

the nozzle mechanism (20) is provided with a nozzle (22) matched with the firing pin (125), the piezoelectric actuating assembly (12) is in transmission connection with the firing pin (125) so as to drive the firing pin (125) to move relative to the nozzle (22), and the dispensing medium extruded into the nozzle (22) is sprayed out of the nozzle (22); a kind of electronic device with high-pressure air-conditioning system

The first adjusting mechanism (30) is arranged on the valve body (11) and is matched and connected with the piezoelectric actuating assembly (12) to adjust the piezoelectric actuating assembly (12), so that the piezoelectric actuating assembly (12) drives the firing pin (125) to adjust the position of the firing pin relative to the nozzle (22).

8. The piezo-injection valve according to claim 7, characterized in that it comprises a second adjustment mechanism (40) provided to the valve body (11); the driving mechanism (10) comprises a pre-tightening spring (13) positioned in the valve body (11), and two opposite ends of the pre-tightening spring (13) are respectively abutted against the piezoelectric actuating assembly (12) and the second adjusting mechanism (40) so as to provide a pre-tightening force for enabling the piezoelectric actuating assembly (12) to have a movement trend away from the nozzle (22);

the second adjusting mechanism (40) is used for adjusting the compression amount of the pre-tightening spring (13).

9. The piezoelectric injection valve according to claim 8, characterized in that the second adjusting mechanism (40) comprises a wedge block (42) and an adjusting member (41), the wedge block (42) being movably arranged at one end of the pre-tightening spring (13) remote from the piezoelectric actuation assembly (12); the adjusting member (41) is provided to the valve body (11) and is configured to operatively move the wedge block (42) so that the wedge block (42) compresses or releases the pretension spring (13).

10. The piezoelectric injection valve according to claim 9, wherein the second adjustment mechanism (40) further comprises an abutment seat (43) movably provided in the valve body (11) in a compression direction of the pretension spring (13), opposite ends of the pretension spring (13) being respectively abutted against the piezoelectric actuation assembly (12) and the abutment seat (43);

the valve body (11) is provided with a third abutting part (a 3) positioned on one side of the abutting seat (43) away from the pre-tightening spring (13), the wedge block (42) is arranged between the abutting seat (43) and the third abutting part (a 3), and the wedge block (42) is provided with a first surface (b 1) abutting against the abutting seat (43) and a second surface (b 2) abutting against the third abutting part (a 3);

one of the first surface (b 1) and the second surface (b 2) is parallel to a dummy plane, the other of which is inclined with respect to the dummy plane, the dummy plane being perpendicular to the compression direction of the pretensioning spring (13).