A piezoelectric injection valve and its calibration method

Abstract

The present invention relates to a piezoelectric jet valve and a calibration method thereof. The calibration method includes: 1) introducing a liquid into the piezoelectric jet valve so that the liquid drips from the nozzle of the piezoelectric jet valve; 2) adjusting the position of the piezoelectric actuator of the piezoelectric jet valve, thereby driving the plunger of the piezoelectric jet valve to move towards the nozzle until the dripping frequency of the nozzle decreases to a preset frequency. In this way, by observing the dripping frequency of the nozzle to determine whether the contact pressure between the plunger and the nozzle is appropriate, since the dripping frequency is convenient for accurate observation and statistics, it avoids over-reliance on the experience of operators, is beneficial to improving the accuracy and consistency of calibration, and improves the stability of the dispensing quality of the piezoelectric jet valve.

Description

Technical Field

[0001] The present invention relates to the technical field of dispensing, and particularly to a piezoelectric injection valve and a calibration method thereof. Background Art

[0002] With the rapid development of the electronics industry, the requirements for electronic packaging are getting higher and higher. For high-demand electronic packaging technologies, non-contact piezoelectric injection valves are increasingly widely used in the field of electronic packaging due to their advantages such as high efficiency and high precision. The main structure of the piezoelectric injection valve consists of a main valve body, a flow channel assembly, a nozzle and a plunger for glue injection, etc. Its main principle is: energize the main valve body, amplify the deformation amount of the piezoelectric actuator through the internal amplification structure, and transmit it to the plunger. The plunger and the nozzle contact in the flow channel assembly to form a cavity, and the plunger reciprocates at high speed to impact the nozzle, ejecting the glue in the cavity to complete dispensing. Therefore, the contact pressure between the plunger and the nozzle has a great influence on the dispensing effect. In order to improve the consistency of dispensing quality, it is necessary to calibrate the contact pressure between the plunger and the nozzle.

[0003] However, in the prior art, during the dispensing operation, the contact pressure between the plunger and the nozzle is adjusted by manually adjusting the up and down movement of the nozzle, which highly depends on the experience of the operator, and the calibration results vary greatly, that is, the consistency of the contact pressure between the plunger and the nozzle calibrated each time is poor, which has an adverse effect on the dispensing quality. Summary of the Invention

[0004] Based on this, in view of the problem that the calibration process of the piezoelectric injection valve in the prior art highly depends on the experience of the operator, and the calibration results vary greatly, thus having an adverse effect on the dispensing quality, it is necessary to provide a piezoelectric injection valve and a calibration method thereof that improve the above defects.

[0005] A calibration method for a piezoelectric injection valve includes the following steps:

[0006] 1) Introduce a liquid into the piezoelectric injection valve so that the liquid drips from the nozzle of the piezoelectric injection valve;

[0007] 2) Adjust the position of the piezoelectric actuator of the piezoelectric injection valve, thereby driving the plunger of the piezoelectric injection valve to move towards the nozzle until the dripping frequency of the nozzle decreases to a preset frequency.

[0008] In one embodiment, after the step 2), it further includes step 3):

[0009] Stop introducing the liquid into the piezoelectric injection valve, and adjust the compression amount of the pre-tightening spring of the piezoelectric injection valve to a preset compression amount.

[0010] In one embodiment, after the step 3), it further includes step 4):

[0011] Continue to introduce the liquid into the piezoelectric injection valve, and observe the dripping frequency of the nozzle;

[0012] If the dripping frequency of the nozzle is greater than the preset frequency, loop to execute step 2) and step 3).

[0013] In one embodiment, after step 4), there is further included step 5):

[0014] Fine-tune the position of the nozzle away from the plunger, and observe the dripping frequency of the nozzle;

[0015] If the dripping frequency of the nozzle is the preset frequency, loop to execute steps 2) to 4).

[0016] In one embodiment, in step 5), the distance for fine-tuning the position of the nozzle does not exceed 1 mm.

[0017] In one embodiment, one end of the pipeline filled with the liquid is connected to the inlet of the piezoelectric injection valve, and 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 the air flow provided by the external air source.

[0018] A piezoelectric injection valve calibrated by applying the calibration method described in any of the above embodiments includes:

[0019] A driving mechanism, including a valve body and a piezoelectric actuation component and a plunger both arranged in the valve body;

[0020] A nozzle mechanism, having a nozzle that cooperates with the plunger, the piezoelectric actuation component is in transmission connection with the plunger to drive the plunger to move relative to the nozzle, and the dispensing medium entering the nozzle is extruded and ejected from the nozzle; and

[0021] A first adjustment mechanism, arranged on the valve body and connected to the piezoelectric actuation component, for adjusting the piezoelectric actuation component so that the piezoelectric actuation component drives the plunger to perform position adjustment relative to the nozzle.

[0022] In one embodiment, the injection valve includes a second adjustment mechanism arranged on the valve body; the driving mechanism includes a pre-tightening spring located in the valve body, and opposite ends of the pre-tightening spring respectively abut against the piezoelectric actuation component and the second adjustment mechanism to provide a pre-tightening force that causes the piezoelectric actuation component to have a movement tendency away from the nozzle;

[0023] The second adjustment mechanism is used to adjust the compression amount of the pre-tightening spring.

[0024] In one embodiment, the second adjustment mechanism includes a wedge block and an adjustment member, wherein the wedge block is movably disposed at one end of the preload spring away from the piezoelectric actuator assembly; the adjustment member is disposed on the valve body and is configured to operably drive the wedge block to move so that the wedge block compresses or releases the preload spring.

[0025] In one embodiment, the second adjustment mechanism further comprises an abutment seat movably connected to the valve body along the compression direction of the preload spring, and opposite ends of the preload spring abut against the piezoelectric actuator assembly and the abutment seat respectively;

[0026] The valve body has a third abutment portion located on a side of the abutment seat away from the preload spring, the wedge block is arranged between the abutment seat and the third abutment portion, and the wedge block has a first surface abutting against the abutment seat and a second surface abutting against the third abutment portion;

[0027] One of the first surface and the second surface is parallel to a virtual plane, and the other of the first surface and the second surface is inclined relative to the virtual plane, and the virtual plane is perpendicular to the compression direction of the preload spring.

[0028] The above-mentioned piezoelectric injection valve and its correction method determine whether the contact pressure between the impact needle and the nozzle is appropriate by observing the dripping frequency of the nozzle. Since the dripping frequency is easy to observe and count accurately, it avoids over-reliance on the operator's experience, which is beneficial to improving the accuracy and consistency of the correction and improving the stability of the piezoelectric injection valve dispensing quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 A schematic diagram of the structure of a piezoelectric injection valve in one embodiment of the present invention;

[0030] Figure 2 for Figure 1 A cross-sectional view of the piezoelectric injection valve shown;

[0031] Figure 3 for Figure 1 A schematic diagram of the cooperation between the nozzle and the striker of the piezoelectric injection valve shown;

[0032] Figure 4 for Figure 1 A schematic structural diagram of a second regulating mechanism of the piezoelectric injection valve shown;

[0033] Figure 5 The figure is a flow chart of a method for calibrating a piezoelectric injection valve in one embodiment of the present invention. DETAILED DESCRIPTION

[0034] To make the above objects, features, and advantages of the present invention more apparent and understandable, the following will provide a detailed description of the specific embodiments of the present invention with reference to the accompanying drawings. A lot of specific details are set forth in the following description to facilitate a full understanding of the present invention. However, the present invention can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without departing from the connotation of the present invention. Therefore, the present invention is not limited by the specific embodiments disclosed below.

[0035] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0036] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of such features. In the description of the present invention, the meaning of "a plurality" is at least two, such as two, three, etc., unless otherwise specifically and clearly defined.

[0037] In the present invention, unless otherwise clearly specified and limited, the terms "mounted", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the internal communication of two elements or the interaction relationship between two elements, unless otherwise clearly limited. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0038] In the present invention, unless otherwise clearly specified and limited, the first feature being "on" or "under" the second feature may be that the first and second features are in direct contact, or the first and second features are indirectly in contact through an intermediate medium. Moreover, the first feature being "above", "over", and "on top of" the second feature may be that the first feature is directly above or obliquely above the second feature, or merely indicates that the first feature has a higher horizontal height than the second feature. The first feature being "under", "beneath", and "underneath" the second feature may be that the first feature is directly below or obliquely below the second feature, or merely indicates that the first feature has a lower horizontal height than the second feature.

[0039] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it may be directly on the other element or there may be a central element. When an element is considered to be "connected to" another element, it may be directly connected to the other element or there may be a central element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are for illustrative purposes only and are not intended to be the only implementation method.

[0040] See also Figures 1 to 3 As shown, one embodiment of the present invention provides a piezoelectric injection valve, including a driving mechanism 10, a nozzle mechanism 20 and a first adjusting mechanism 30. The driving mechanism 10 includes a valve body 11 and 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 cooperates with the striker 125. The piezoelectric actuator assembly 12 is transmission-connected to the striker 125 to drive the striker 125 to move relative to the nozzle 22, and squeeze the dispensing medium entering the nozzle 22 to be ejected from the nozzle 22, thereby achieving dispensing. The first adjusting mechanism 30 is disposed on the valve body 11, and is cooperatively connected with the piezoelectric actuator assembly 12, and is used to adjust the piezoelectric actuator assembly 12, so that the piezoelectric actuator assembly 12 drives the striker 125 to adjust its position relative to the nozzle 22, thereby adjusting the contact pressure between the striker 125 and the nozzle 22.

[0041] Specifically in the embodiment, the nozzle mechanism 20 also includes a flow channel seat 21, which is fixedly connected to the valve body 11, and the nozzle 22 is arranged on the flow channel seat 21, and the flow channel seat 21 has a flow channel 23 connected to the nozzle 22, and the inlet of the flow channel 23 is provided with a Luer connector 24 for connecting with an external pipeline (not shown), so that the dispensing medium can enter the flow channel 23 through the external pipeline. The outlet of the flow channel 23 is connected to the nozzle 22, so that the dispensing medium entering the flow channel 23 can enter the nozzle 22, and then dispensing is achieved under the cooperation of the nozzle 22 and the striker 125.

[0042] Furthermore, the nozzle 22 is threadedly connected to the flow channel seat 21 , and when the nozzle 22 is screwed, the nozzle 22 can move closer to or away from the striker 125 .

[0043] Specifically in the embodiment, the piezoelectric actuation assembly 12 includes a piezoelectric actuator 121 and a magnifying lever 123. The driving mechanism 10 further includes a preloading spring 13 located within the valve body 11. The magnifying lever 123 has a hinge portion a1, a first abutting portion a2, and a second abutting portion a3, and the hinge portion a1 is hingedly connected to the valve body 11. The first abutting portion a2 is located between the hinge portion a1 and the second abutting portion a3. The piezoelectric actuator 121 is movably disposed within 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 magnifying lever 123. The ejector pin 125 is movably disposed within the valve body 11, and one end of the ejector pin 125 cooperates with the nozzle 22, and the other end of the ejector pin 125 abuts against the second abutting portion a3 of the magnifying lever 123. The preloading spring 13 is sleeved outside the ejector pin 125, and one end of the preloading spring 13 abuts against the second abutting portion a3 of the magnifying lever 123, and the other end of the preloading spring 13 abuts against the valve body 11. Thus, during the dispensing operation, the piezoelectric actuator 121 is powered on and starts to vibrate up and down, causing the magnifying lever 123 to swing up and down under the combined action of the up and down vibration generated by the piezoelectric actuator 121 and the preloading force provided by the preloading spring 13, thereby driving the ejector pin 125 to reciprocate up and down, so that the ejector pin 125 continuously squeezes the ejection medium to be ejected from the nozzle 22, that is, dispensing is achieved.

[0044] Further, a return spring is sleeved outside the ejector pin 125, and the return spring is used to provide a return force for driving the ejector pin 125 to keep abutting against the second abutting portion a3 of the magnifying lever 123. Thus, when the magnifying lever 123 swings in a direction away from the nozzle 22 under the action of the preloading force provided by the preloading spring 13 (i.e., the upward swing as shown in Figure 2 ), the ejector pin 125 also moves away from the nozzle 22 following the magnifying lever 123 under the action of the return force provided by the return spring. When the magnifying lever 123 swings in a direction close to the nozzle 22 driven by the piezoelectric actuation assembly 12 (i.e., the downward swing as shown in Figure 2 ), the magnifying lever 123 drives the ejector pin 125 to move close to the nozzle 22 (i.e., the downward movement as shown in Figure 2 ).

[0045] Further, the first adjusting mechanism 30 includes an adjusting screw 31, and the adjusting screw 31 is threadedly connected to the valve body 11, and one end of the adjusting screw 31 abuts against the end of the piezoelectric actuator 121 away from the magnifying lever 123. Thus, when correcting the contact pressure between the ejector pin 125 and the nozzle 22, the adjusting screw 31 can be rotated forward or backward to drive the piezoelectric actuator 121 to move to adjust its position. Further, the piezoelectric actuator 121 can drive the magnifying lever 123 to swing, and then the magnifying lever 123 drives the ejector pin 125 to move close to or away from the nozzle 22, so as to achieve the purpose of adjusting the contact pressure between the ejector pin 125 and the nozzle 22.

[0046] Specifically in the embodiment, the piezoelectric injection valve further includes a second adjustment mechanism 40 disposed on the valve body 11, and one end of the preload spring 13 away from the second abutment portion a3 abuts against the second adjustment mechanism 40. The preload spring 13 is used to provide a preload force that causes the amplification lever 123 to have a movement tendency away from the nozzle 22. Figure 2 As shown, the preload spring 13 applies an upward preload force to the second abutment portion a3 of the amplification lever 123. The second adjustment mechanism 40 is used to adjust the compression amount of the preload spring 13, thereby adjusting the magnitude of the preload force applied to the amplification lever 123.

[0047] It should be noted that the preload force provided by the preload spring 13 is crucial to the stability of the piezoelectric actuator 121 driving the striker 125 to reciprocate up and down. Therefore, in order to ensure the quality of dispensing, the preload force provided by the preload spring 13 needs to be within the design range (designed according to the specific valve body specifications) 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 adjustment mechanism 30, the position of the amplification lever 123 will change, so that the compression amount of the preload spring 13 will also change (that is, the preload force provided by the preload spring 13 will also change). At this time, the compression amount of the preload spring 13 can be adjusted by the second adjustment mechanism 40, so that the compression amount of the preload spring 13 meets the demand, ensuring that the preload force provided by the preload spring 13 is within the design range.

[0048] See also Figure 4 As shown, further, the second adjustment mechanism 40 includes a wedge block 42 and an adjustment member 41. The wedge block 42 is movably disposed at one end of the preload spring 13 away from the second abutment portion a3. The adjustment member 41 is disposed on the valve body 11, and is configured to operably drive the wedge block 42 to move so that the wedge block 42 compresses or releases the preload spring 13, thereby adjusting the compression amount of the preload spring 13, and further adjusting the size of the preload force provided by the preload spring 13. Optionally, the adjustment member 41 is threadedly connected to the valve body 11, and one end of the adjustment member 41 is connected to the wedge block 42, so that the adjustment member 41 can be screwed forward or reversely to drive the wedge block 42 to move and compress or release the preload spring 13, that is, to adjust the compression amount of the preload spring 13.

[0049] Further, the second adjusting mechanism 40 further includes an abutting seat 43 which is movably disposed in the valve body 11 along the compression direction of the pre-tightening spring 13. The two opposite ends of the pre-tightening spring 13 respectively abut against the piezoelectric actuating assembly 12 and the abutting seat 43. The valve body 11 has a third abutting portion a3 on the side of the abutting seat 43 away from the pre-tightening spring 13. The wedge block 42 is disposed between the abutting seat 43 and the third abutting portion a3, and the wedge block 42 has a first surface b1 abutting against the abutting seat 43 and a second surface b2 abutting against the third abutting portion a3. One of the first surface b1 and the second surface b2 is parallel to a virtual plane, and the other is inclined relative to the virtual plane, and the virtual plane is perpendicular to the compression direction of the pre-tightening spring 13.

[0050] Specifically Figure 2 or Figure 4 In the illustrated embodiment, the virtual plane is a horizontal plane, the first surface b1 is parallel to the virtual plane (i.e., perpendicular to the compression direction of the pre-tightening spring 13), and the second surface b2 is inclined relative to the virtual plane. Thus, when the adjusting member 41 is screwed and drives the wedge block 42 to move to the right, under the guiding action of the second surface b2, the wedge block 42 squeezes the abutting seat 43 to move upward, thereby increasing the compression amount of the pre-tightening spring 13. When the adjusting member 41 is screwed and drives the wedge block 42 to move to the left, under the guiding action of the second surface b2, the wedge block 42 generates a downward displacement, so that under the pressing of the pre-tightening spring 13, the abutting seat 43 moves downward, thereby reducing the compression amount of the pre-tightening spring 13.

[0051] The following Figure 2 illustrates the operation processes of the first adjusting mechanism 30 and the second adjusting mechanism 40:

[0052] When it is necessary to adjust the striker 125 to be close to the nozzle 22, the adjusting screw 31 is screwed to drive the piezoelectric actuator 121 to move downward, so that the piezoelectric actuator 121 drives the amplification lever 123 to rotate counterclockwise against the pre-tightening force of the pre-tightening spring 13, thereby driving the striker 125 to move downward close to the nozzle 22.

[0053] When it is necessary 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 pre-tightening force provided by the pre-tightening spring 13, thereby causing the striker 125 to move upward away from the nozzle 22 under the action of the return spring.

[0054] When it is necessary to increase the compression amount of the pre-tightening spring 13 (i.e., increase the pre-tightening force provided by the pre-tightening spring 13), the adjusting member 41 is screwed to drive the wedge block 42 to move to the right, so that the wedge block 42 squeezes the abutting seat 43 to move upward, thereby compressing the pre-tightening spring 13, that is, increasing the compression amount of the pre-tightening spring 13.

[0055] When it is necessary to reduce the compression amount of the preloading spring 13 (i.e., when reducing the preloading force provided by the preloading spring 13), turn the adjusting member 41 to drive the wedge block 42 to move leftward, so that the preloading spring 13 squeezes the abutting seat 43 to move downward, thereby reducing the compression amount of the preloading spring 13.

[0056] Please refer to Figure 5 As shown, based on the above piezoelectric injection valve, the present invention also provides a calibration method for a piezoelectric injection valve, and the calibration method includes the following steps:

[0057] S10. Introduce a liquid with good fluidity into the flow channel 23 of the piezoelectric injection valve, so that the liquid enters the nozzle 22 from the flow channel 23 and drips out from the nozzle 22. Specifically, the liquid is contained in a pipeline, and one end of the pipeline is connected to the inlet of the piezoelectric injection valve (i.e., the above-mentioned Luer connector 24), and the other end of the pipeline is communicated with an external air source. The air flow provided by the external air source is used to press the liquid in the pipeline into the flow channel 23 of the piezoelectric injection valve, and then drip from the nozzle 22. In this way, 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 channel 23 of the piezoelectric injection valve. When the external air source is turned off, the liquid in the pipeline stops entering the flow channel 23 of the piezoelectric injection valve.

[0058] S20. Adjust the position of the piezoelectric actuator 121 of the piezoelectric injection valve, so as to drive the plunger 125 of the piezoelectric injection valve to move towards the nozzle 22 until the dripping frequency of the nozzle 22 is reduced to a preset frequency. Specifically, in order to ensure that the plunger 125 is separated from the nozzle 22 when starting to adjust the position of the plunger 125, the piezoelectric actuator 121 needs to be energized, and the above-mentioned adjusting screw 31 is turned to drive the piezoelectric actuator 121 to move upward, so that the plunger 125 moves upward under the action of the return spring, so that the plunger 125 is separated from the nozzle 22. Then, turn the above-mentioned adjusting screw 31 in the reverse direction to drive the piezoelectric actuator 121 to move downward, so that the plunger 125 gradually approaches the nozzle 22. During the process of adjusting the plunger 125 to gradually approach the nozzle 22, observe the change in the dripping frequency of the nozzle 22, and stop turning the adjusting screw 31 until the dripping frequency of the nozzle 22 is reduced to the preset frequency.

[0059] In this way, by observing the dripping frequency of the nozzle 22 to judge whether the contact pressure between the plunger 125 and the nozzle 22 is appropriate. Since the dripping frequency is convenient for accurate observation and statistics, it avoids over-reliance on the experience of operators, is beneficial to improving the accuracy and consistency of calibration, and improves the stability of the dispensing quality of the piezoelectric injection valve.

[0060] Optionally, the preset frequency may be a specific value, for example, 0. When the droplet dripping frequency of the nozzle 22 is 0, no liquid droplets drip from the nozzle 22. That is to say, during the process of adjusting the striker 125 to gradually approach the nozzle 22 in step S20, when there is no liquid dripping from the nozzle 22, stop turning the adjusting screw 31. Of course, in other embodiments, the preset frequency may also be a value slightly greater than 0, which can be set according to the fluidity of the liquid and the specifications of the piezoelectric injection valve, and is not limited herein.

[0061] Of course, in other embodiments, the preset frequency may also be a frequency range (for example, a range value slightly greater than 0), which can be set according to the fluidity of the liquid and the specifications of the piezoelectric injection valve, and is not limited herein.

[0062] Specifically in the embodiment, the liquid introduced into the flow channel 23 of the piezoelectric injection valve may be a volatile liquid, such as alcohol. In this way, by utilizing the volatile characteristic of the liquid, it is possible to avoid the residue of the liquid in the flow channel 23 and the nozzle 22 of the piezoelectric injection valve, that is, to prevent the dispensing medium entering the piezoelectric injection valve from mixing with the residual liquid during subsequent dispensing operations, thereby affecting the performance of the dispensing medium.

[0063] It should be noted that the pre-tightening force applied by the pre-tightening spring 13 to the amplification lever 123 affects the stability of the up-and-down reciprocating movement of the striker 125. Therefore, it is necessary to ensure that the pre-tightening force applied by the pre-tightening spring 13 to the amplification lever 123 meets the design requirements. However, when adjusting the contact pressure between the striker 125 and the nozzle 22 in step S20, the compression amount of the pre-tightening spring 13 will inevitably change, resulting in an increase or decrease in the pre-tightening force applied by the pre-tightening spring 13 to the amplification lever 123, thereby affecting the dispensing quality. To overcome the above defects, in one embodiment, after the above step S20, there is also a step S30:

[0064] Stop introducing liquid into the flow channel 23 of the piezoelectric injection valve, and adjust the compression amount of the pre-tightening spring 13 of the piezoelectric injection valve to a preset compression amount.

[0065] In this way, after the position of the striker 125 is adjusted in place in step S20, then adjust the compression amount of the pre-tightening spring 13 to the preset compression amount, so as to ensure that the pre-tightening force applied by the pre-tightening spring 13 to the amplification lever 123 meets the design requirements, which is beneficial to improving the dispensing quality.

[0066] Further, step S20 specifically includes: powering off the piezoelectric actuator 121 and closing the external gas source, so that the liquid in the pipeline stops entering the flow channel 23 of the piezoelectric injection valve. Then, use a measuring tool to measure the length of the preloading spring 13, so as to obtain the compression amount of the preloading spring 13 at this time. Then, drive the preloading spring 13 to elongate or shorten by screwing the adjusting member 41 until the compression amount of the pressing spring reaches the preset compression amount. Of course, the preset compression amount can be a specific value or a range, which is set according to the specifications of the piezoelectric injection valve and the like, and is not limited herein.

[0067] Specifically in the embodiment, after step S30, there is also step S40 (that is, the step of judging whether the contact pressure between the impact pin 125 and the nozzle 22 is too small):

[0068] Continue to introduce liquid into the flow channel 23 of the piezoelectric injection valve, and observe the dripping frequency of the nozzle 22;

[0069] If the dripping frequency of the nozzle 22 is greater than the above preset frequency, it indicates that the contact pressure between the impact pin 125 and the nozzle 22 is too small at this time. At this time, it is necessary to repeatedly execute the above steps S20 and S30 to re-adjust the contact pressure between the impact pin 125 and the nozzle 22; if the dripping frequency of the nozzle 22 maintains the above preset frequency, it indicates that the contact pressure between the impact pin 125 and the nozzle 22 is not too small. In this way, by introducing liquid into the piezoelectric injection valve again and judging whether the contact pressure between the impact pin 125 and the nozzle 22 is too small according to the dripping frequency of the nozzle 22, the calibration accuracy of the contact pressure between the impact pin 125 and the nozzle 22 is further improved. It should be noted that the piezoelectric actuator 121 is re-powered on when step S40 is executed.

[0070] Specifically in the embodiment, after step S40, there is also step S50 (that is, the step of judging whether the contact pressure between the impact pin 125 and the nozzle 22 is too large):

[0071] Fine-tune the position of the nozzle 22 in the direction away from the impact pin 125;

[0072] If the dripping frequency of the nozzle 22 is the above preset frequency, it indicates that the contact pressure between the impact pin 125 and the nozzle 22 is too large. At this time, it is necessary to repeatedly execute steps S20 to S40. If the dripping frequency of the nozzle 22 is greater than the above preset frequency, it indicates that the contact pressure between the impact pin 125 and the nozzle 22 is not too large. In this way, by introducing liquid into the piezoelectric injection valve again and judging whether the contact pressure between the impact pin 125 and the nozzle 22 is too large according to the dripping frequency of the nozzle 22, the calibration accuracy of the contact pressure between the impact pin 125 and the nozzle 22 is further improved.

[0073] In step S50, the adjustment of the position of the nozzle 22 should not be too large or too small. If the position adjustment of the nozzle 22 is too large, the avoidance of the droplet ejection frequency of the nozzle 22 will increase, so the effect of judging whether the contact pressure between the plunger 125 and the nozzle 22 is too large cannot be achieved. When the position adjustment of the nozzle 22 is too small, the phenomenon that the droplet ejection frequency remains unchanged will also occur when the contact pressure between the plunger 125 and the nozzle 22 is not too large. Therefore, the effect of judging whether the contact pressure between the plunger 125 and the nozzle 22 is too large cannot be achieved. To overcome the above defects, in some embodiments, the distance of fine-tuning the position of the nozzle 22 in step S50 does not exceed 1 mm, so as to ensure that the contact pressure between the plunger 125 and the nozzle 22 can be accurately judged by the droplet ejection frequency of the nozzle 22.

[0074] It should be noted that after the position of the nozzle 22 is fine-tuned in step S50, the position of the nozzle 22 needs to be reset. For example, initially the nozzle 22 is at the tightened limit position (i.e., the position closest to the plunger 125). In step S50, the nozzle 22 is loosened so that the nozzle 22 moves away from the plunger 125 by no more than 1 mm (i.e., the fine-tuning distance is controlled by controlling the number of turns of loosening the nozzle 22). After judging whether the contact pressure between the nozzle 22 and the plunger 125 is too large, the nozzle 22 needs to be tightened to the limit position (i.e., reset).

[0075] The calibration method of the piezoelectric jet valve of the present application has at least the following beneficial effects:

[0076] By observing the droplet ejection frequency of the nozzle 22, the calibration of the contact pressure between the plunger 125 and the nozzle 22 is realized, and the calibration deviation of the contact pressure between the plunger 125 and the nozzle 22 caused by multiple calibrations of the same valve body, or calibrations of different valve bodies, or calibrations by different technicians, etc. is reduced or eliminated, which is beneficial to improving the consistency of the dispensing performance of the piezoelectric jet valve;

[0077] On the premise of realizing the calibration of the contact pressure between the plunger 125 and the nozzle 22, the compression amount of the pre-tightening spring 13 is also calibrated to ensure that the magnitude of the pre-tightening force exerted by the pre-tightening spring 13 on the piezoelectric actuator 121 meets the requirements, thereby ensuring the performance and accuracy of the piezoelectric jet valve;

[0078] The contact pressure between the plunger 125 and the nozzle 22 is adjusted by the first adjustment screw 31 of the first adjustment mechanism 30, and the compression amount of the pre-tightening spring 13 is adjusted by the adjusting member 41 of the second adjustment mechanism 40. Moreover, the structures of the first adjustment mechanism 30 and the second adjustment mechanism 40 are simple and do not change the main structure of the piezoelectric jet valve, so the influence on the performance of the piezoelectric jet valve is small, further ensuring the dispensing quality.

[0079] The technical features of the above-described embodiments can be combined arbitrarily. For the sake of brevity of description, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered as falling within the scope described in this specification.

[0080] The above-described embodiments only express several implementation manners of the present invention. The description is relatively specific and detailed, but it should not be construed as a limitation on the scope of the invention patent. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several modifications and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the appended claims.

Claims

1. A calibration method for a piezoelectric injection valve, characterized in that The following steps are involved: 1) introducing liquid into the piezoelectric injection valve so that the liquid drips from a nozzle (22) of the piezoelectric injection valve; 2) adjusting the position of the piezoelectric actuator (121) of the piezoelectric injection valve, thereby driving the striker (125) of the piezoelectric injection valve to move toward the nozzle (22) until the dripping frequency of the nozzle (22) is reduced to a preset frequency; After step 2), step 3) is also included: Stopping the flow of the liquid into the piezoelectric injection valve, and adjusting the compression amount of the preload spring (13) of the piezoelectric injection valve to a preset compression amount; After step 3), step 4) is also included: Continue to introduce the liquid into the piezoelectric injection valve and observe the dripping frequency of the nozzle (22); If the dripping frequency of the nozzle (22) is greater than the preset frequency, then the steps 2) and 3) are executed cyclically); After step 4), step 5) is also included: Finely adjusting the position of the nozzle (22) in a direction away from the striker (125), and observing the dripping frequency of the nozzle (22); If the dripping frequency of the nozzle (22) is the preset frequency, steps 2) to 4) are executed cyclically.

2. The calibration method of the piezoelectric injection valve according to claim 1, wherein, In step 5), the distance of fine adjustment of the position of the nozzle (22) does not exceed 1 mm.

3. The calibration method of the piezoelectric injection valve according to claim 1, characterized in that, One end of the pipeline containing the liquid is connected to the inlet of the piezoelectric injection valve, and the other end of the pipeline is connected to an external air source, and the airflow provided by the external air source is used to press the liquid in the pipeline into the piezoelectric injection valve.

4. The calibration method of the piezoelectric injection valve according to any one of claims 1 to 3, characterized in that, The piezoelectric injection valve comprises: A driving mechanism (10) comprising a valve body (11) and a piezoelectric actuating assembly (12) and a striker (125) both disposed in the valve body (11); The nozzle mechanism (20) comprises a nozzle (22) cooperating with the striker (125), the piezoelectric actuator assembly (12) being drivingly connected to the striker (125) so as to drive the striker (125) to move relative to the nozzle (22), and to squeeze the dispensing medium entering the nozzle (22) to be ejected from the nozzle (22); and A first adjustment mechanism (30) is disposed on the valve body (11) and is coupled to the piezoelectric actuating assembly (12) for adjusting the piezoelectric actuating assembly (12) so that the piezoelectric actuating assembly (12) drives the striker (125) to adjust its position relative to the nozzle (22).

5. The calibration method of the piezoelectric injection valve according to claim 4, characterized in that, The piezoelectric injection valve comprises a second adjustment mechanism (40) arranged on the valve body (11); the drive mechanism (10) comprises a preload spring (13) located in the valve body (11), and opposite ends of the preload spring (13) respectively abut against the piezoelectric actuating component (12) and the second adjustment mechanism (40) to provide a preload force that causes the piezoelectric actuating component (12) to have a movement tendency away from the nozzle (22); The second adjustment mechanism (40) is used to adjust the compression amount of the preload spring (13).

6. The calibration method of the piezoelectric injection valve according to claim 5, characterized in that The second adjusting mechanism (40) includes a wedge block (42) and an adjusting member (41). The wedge block (42) is movably arranged at one end of the pre-tightening spring (13) away from the piezoelectric actuating assembly (12); the adjusting member (41) is arranged on the valve body (11) and is configured to operably drive the wedge block (42) to move so that the wedge block (42) compresses or releases the pre-tightening spring (13).

7. The calibration method of the piezoelectric injection valve according to claim 6, characterized in that, The second adjusting mechanism (40) further includes an abutting seat (43) movably arranged in the valve body (11) along the compression direction of the pre-tightening spring (13). The opposite ends of the pre-tightening spring (13) respectively abut against the piezoelectric actuating assembly (12) and the abutting seat (43); The valve body (11) has a third abutting portion (a3) on a side of the abutting seat (43) facing away from the pre-tightening spring (13). The wedge block (42) is arranged between the abutting seat (43) and the third abutting portion (a3). The wedge block (42) has a first surface (b1) abutting against the abutting seat (43) and a second surface (b2) abutting against the third abutting portion (a3); One of the first surface (b1) and the second surface (b2) is parallel to a virtual plane, and the other is inclined relative to the virtual plane. The virtual plane is perpendicular to the compression direction of the pre-tightening spring (13).

Images