Improved method for high-speed dispensing

Abstract

The invention provides an improvement method for high-speed dispensing, a Tesla valve is connected in series in a glue runner, the Tesla valve is composed of a repeated curve and a straight pipeline, a reverse inlet of the Tesla valve is connected with a glue supply direction, a forward inlet of the Tesla valve is connected with a glue outlet direction, and the straight pipeline is connected with the curve. The Tesla valve is adopted, due to the fact that the Tesla valve is not provided with a movable part, the service life is long, resistance generated by glue collision can play a good stopping role, all parts in a flow channel are effectively protected, the water hammer effect and fluid erosion are reduced, and the service life of the Tesla valve is prolonged. The requirement for accurately controlling the driving pulse time duration is reduced, so that the driving control of the glue pressure is simplified, the ratio of the cross sectional area of the curve to the cross sectional area of the straight pipeline is set according to the dispensing frequency of the dispensing machine, and meanwhile, external power is driven according to the frequency, so that the whole runner system operates in a coordinated manner; and the use precision and the service life of the runner system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of dispensing machines, and particularly to an improved method for high-speed dispensing. Background Art

[0002] Glue is often highly viscous, and the viscosity variation range is very large. The viscosity variation ranges of different types of glue are from dozens of mPa·s (millipascal seconds) to hundreds of thousands of mPa·s (millipascal seconds). Driving the movement of glue in a dispensing machine often requires high-pressure gas or a pressure piston. During the dispensing process, intermittent control of the glue flow is needed. Currently, commonly used valves include metering valves, screw valves, jet valves, pneumatic valves, diaphragm valves, needle valves, and spray valves. The glue flows for a while and stops for a while in the flow channel. During the high-frequency and high-speed dispensing process, the impact of the glue has an adverse effect on the moving parts connected to the flow channel, such as water hammer damage and fluid erosion. As the moving parts wear, precise control of the dispensing volume becomes difficult with the increase in the usage time. Therefore, it is necessary to design a special flow channel structure that can assist in controlling the stop of glue at a high frequency, acting as a valve, can withstand a large pressure range, and at the same time reduce the use of moving parts, so that the precise dispensing volume can maintain good continuity. Summary of the Invention

[0003] Aiming at the deficiencies of the prior art, the present invention attempts to overcome the above defects. Therefore, the present invention provides an improved method for high-speed dispensing, which solves the problem of rapid stop of glue during the high-speed dispensing process and improves the durability of the flow channel and the stability of dispensing.

[0004] To achieve the above object, the present invention is realized through the following technical solutions: An improved method for high-speed dispensing, in which a Tesla valve is connected in series in the glue flow channel. The Tesla valve is composed of repeated bends and straight pipes. The reverse inlet of the Tesla valve is connected to the glue supply direction, and the forward inlet of the Tesla valve is connected to the glue outlet direction, that is, the reverse flow direction of the Tesla valve is consistent with the glue flow direction.

[0005] Further, the relationship between the dispensing frequency f of the glue and the cross-sectional area S1 of the bend and the cross-sectional area S2 of the straight pipe is as follows: f = A × S1 / S2. The value range of the coefficient A is from 0.8 to 2.5, where the unit of f is times per second.

[0006] Further, the relationship between the single dispensing volume V and the cross-sectional area S2 of the straight pipe is as follows: V = B × S2. The value range of the coefficient B is from 0.001 to 0.01, where the unit of S2 is square millimeters and the unit of V is cubic millimeters.

[0007] Furthermore, the relationship between the cross-sectional area S2 of the straight pipe and the glue viscosity η is as follows: S2 = C × log(η), where the value range of the coefficient C is from 0.01 to 2. Here, the unit of S2 is square millimeters, and the unit of η is millipascal seconds.

[0008] Furthermore, the number of repetitions of the bend and the straight pipe is greater than or equal to 2 times.

[0009] Furthermore, when the viscosity of the glue is less than 1000 millipascal seconds, the reverse inlet of the Tesla valve is directly connected to the bend, and the forward inlet of the Tesla valve is directly connected to the straight pipe.

[0010] Furthermore, when the viscosity of the glue is greater than 1000 millipascal seconds, the reverse inlet and the forward inlet of the Tesla valve are directly connected to the straight pipe.

[0011] Compared with the prior art, the present invention has the following beneficial effects: When the dispenser is working, the glue is driven by intermittent pressure and enters the Tesla valve from the reverse inlet of the Tesla valve, and then it will be split. One way is along the straight pipe, and the other way is along the bend. When the two-way glue converges again, because the glue along the bend and the glue along the straight pipe have opposite components in the flow direction, they will collide, thereby generating resistance to the glue in the straight pipe. At the position where the two-way glue converges again, the glue at this part flows smoothly under the drive of intermittent pressure, realizing the glue dispensing at the dispensing head. When dispensing at high frequency, greater resistance is required to stop the glue. Therefore, it is necessary to increase the cross-sectional area of the bend so that the cross-sectional area of the bend is greater than that of the straight pipe; in addition, the single glue dispensing volume is proportional to the cross-sectional area of the straight pipe. The larger the cross-sectional area of the straight pipe, the larger the single glue dispensing volume; for glues with different viscosities, the more viscous the glue, the greater the cross-sectional area of the straight pipe required; the present invention adopts a Tesla valve. Since there are no moving parts, it has a long service life. The resistance generated by the collision of the glue can play a good stopping role, effectively protecting each component in the flow channel, reducing the water hammer effect and fluid erosion, and playing a good role in the process of high-speed glue dispensing. At the same time, by setting the cross-sectional area of the straight pipe, the single glue dispensing volume can be controlled, reducing the requirement for accurately controlling the driving pulse time length. In this way, the driving control of the glue pressure is simplified, and the accuracy and service life of the driving system are improved. According to the glue dispensing frequency of the dispenser, set the ratio between the cross-sectional area of the bend and the cross-sectional area of the straight pipe, and at the same time let the external power drive according to this frequency, so that the entire flow channel system operates in coordination, improving the use accuracy and service life of the flow channel system. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 : Schematic diagram of a single group of bend and straight pipe connecting the reverse inlet and the forward inlet; Figure 2: Schematic diagram of two sets of curved channels and straight pipes applying high-viscosity glue to connect the reverse inlet and the forward inlet; Figure 3 : Schematic diagram of two sets of curved channels and straight pipes applying low-viscosity glue to connect the reverse inlet and the forward inlet; Figure 4 : Schematic diagram of four sets of curved channels and straight pipes applying high-viscosity glue to connect the reverse inlet and the forward inlet; Figure 5 : Schematic diagram of four sets of curved channels and straight pipes applying low-viscosity glue to connect the reverse inlet and the forward inlet; In the figure: 1. Curved channel; 2. Straight pipe; 3. Reverse inlet; 4. Forward inlet. Detailed implementation mode

[0013] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0014] The present invention provides an improved method for high-speed dispensing, as Figure 1 shown, a Tesla valve is connected in series in the glue flow channel. The Tesla valve is composed of at least one set of curved channels 1 and straight pipes 2. The reverse inlet 3 of the Tesla valve is connected to the glue supply direction, and the forward inlet 4 of the Tesla valve is connected to the glue outlet direction, that is, the reverse flow direction of the Tesla valve is consistent with the flow direction of the glue.

[0015] Embodiment 1 As Figure 2 shown, the Tesla valve is composed of two sets of curved channels 1 and straight pipes 2. When applied to a viscosity greater than 1000 millipascal seconds, the reverse inlet 3 and the forward inlet 4 of the Tesla valve are linearly connected to the straight pipe 2. This setting is beneficial to the transportation of high-viscosity glue.

[0016] Embodiment 2 As Figure 3 shown, the Tesla valve is composed of two sets of curved channels 1 and straight pipes 2. When applied to a glue viscosity less than 1000 millipascal seconds, the reverse inlet 3 of the Tesla valve is linearly connected to the curved channel 1, and the forward inlet 4 of the Tesla valve is linearly connected to the straight pipe 2. This setting is beneficial to the stop of low-viscosity glue.

[0017] Embodiment 3 As Figure 4As shown, the Tesla valve is composed of four groups of curved channels 1 and straight pipes 2. When applied to situations where the viscosity is greater than 1000 millipascal - seconds, the reverse inlet 3 and the forward inlet 4 of the Tesla valve are linearly connected to the straight pipe 2. This setting is beneficial for the transportation of high - viscosity glue.

[0018] Embodiment Four As Figure 5 shown, the Tesla valve is composed of four groups of curved channels 1 and straight pipes 2. When applied to situations where the viscosity of the glue is less than 1000 millipascal - seconds, the reverse inlet 3 of the Tesla valve is linearly connected to the curved channel 1, and the forward inlet 4 of the Tesla valve is linearly connected to the straight pipe 2. This setting is beneficial for the stop of low - viscosity glue.

[0019] The Tesla valve is composed of a steel bottom plate and a glass cover plate. The repeated curved channels and straight pipes are set in the steel bottom plate through CNC technology. The glass cover plate and the steel bottom plate are covered and sealed. The reverse inlet of the Tesla valve is connected to the glue supply direction, and the forward inlet of the Tesla valve is connected to the glue outlet direction. Initially, first let the glue flow slowly to fill the curved channels and straight pipes with glue to avoid filling bubbles in the middle, and check whether all the bubbles are discharged through the glass cover plate.

[0020] The relationship between the dispensing frequency f of the glue and the cross - sectional area S1 of the curved channel 1 and the cross - sectional area S2 of the straight pipe 2 is as follows: f = A×S1 / S2 The value range of the coefficient A is from 0.8 to 2.5. Among them, the unit of f is times per second. The relationship between the single - dispensing volume V and the cross - sectional area S2 of the straight pipe 2 is as follows: V = B×S2 The value range of the coefficient B is from 0.001 to 0.01. Among them, the unit of S2 is square millimeters, and the unit of V is cubic millimeters. The relationship between the cross - sectional area S2 of the straight pipe 2 and the glue viscosity η is as follows: S2 = C×log(η) The value range of the coefficient C is from 0.01 to 2. Among them, the unit of S2 is square millimeters, and the unit of η is millipascal - seconds.

[0021] Working principle: When the dispensing machine is working, the glue enters the Tesla valve from the reverse inlet 3 of the Tesla valve under the drive of intermittent pressure and will be split. One part flows along the straight pipe 2 and the other part flows along the bend 1. When the two parts of the glue converge again, the glue flowing along the bend 1 and the glue flowing along the straight pipe 2 have opposite flow direction components and will collide, thus generating resistance to the glue in the straight pipe 2. At the position where the two parts of the glue converge again, the glue at this part flows smoothly under the drive of intermittent pressure, realizing the glue dispensing at the dispensing head. When performing high-frequency dispensing, greater resistance is required to stop the glue. Therefore, it is necessary to increase the cross-sectional area of the bend 1 so that the cross-sectional area of the bend 1 is larger than that of the straight pipe 2. In addition, the single dispensing volume is proportional to the cross-sectional area of the straight pipe 2. The larger the cross-sectional area of the straight pipe 2, the larger the single dispensing volume. For glues with different viscosities, the more viscous the glue, the larger the cross-sectional area of the straight pipe 2 is required. The present invention adopts a Tesla valve. Since there are no moving parts, it has a long service life. The resistance generated by the collision of the glue can play a good stopping role, effectively protecting each component in the flow channel, reducing the water hammer effect and fluid erosion, and playing a good role in the process of high-speed dispensing. At the same time, by setting the cross-sectional area of the straight pipe 2, the single dispensing volume can be controlled, reducing the requirement for accurately controlling the driving pulse time length. In this way, the driving control of the glue pressure is simplified, and the accuracy and service life of the driving system are improved. According to the dispensing frequency of the dispensing machine, the ratio between the cross-sectional area of the bend 1 and the cross-sectional area of the straight pipe 2 is set, and at the same time, the external power is driven according to this frequency, so that the entire flow channel system operates in coordination, improving the use accuracy and service life of the flow channel system.

[0022] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made therein without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. An improved method for high-speed dispensing, characterized in that: A Tesla valve is connected in series in the glue flow channel. The Tesla valve is composed of repeated bends (1) and straight pipes (2). The reverse inlet (3) of the Tesla valve is connected to the glue supply direction, and the forward inlet (4) of the Tesla valve is connected to the glue discharge direction. That is, the reverse flow direction of the Tesla valve is consistent with the flow direction of the glue.

2. The improved method for high-speed dispensing according to claim 1, characterized in that: The relationship between the glue dispensing frequency f and the cross-sectional area S1 of the curved channel (1) and the cross-sectional area S2 of the straight channel (2) is as follows: f=A×S1 / S2 The coefficient A has a value range of 0.8 to 2.5, where f is expressed in times per second.

3. The improved method for high-speed dispensing according to claim 1, characterized in that: The relationship between the single dispensing volume V and the cross-sectional area S2 of the straight pipe is as follows: V=B×S2 The value range of coefficient B is 0.001 to 0.01, where the unit of S2 is square millimeter and the unit of V is cubic millimeter.

4. The improved method for high-speed dispensing according to claim 1, characterized in that: The relationship between the cross-sectional area S2 of the straight pipe (2) and the viscosity η of the glue is as follows: S2=C×log(η) The coefficient C has a numerical range of 0.01 to 2, where S2 is expressed in square millimeters and η is expressed in milliPascal seconds.

5. The improved method for high-speed dispensing according to claim 1, characterized in that: The number of repetitions of the curved channel (1) and the straight pipe (2) is greater than or equal to 2 times.

6. The improved method for high-speed dispensing according to claim 1, characterized in that: When the viscosity of the glue is less than 1000 milliPascal seconds, the reverse inlet (3) of the Tesla valve is connected to the curved channel (1) in a straight line, and the forward inlet (4) of the Tesla valve is connected to the straight pipeline (2) in a straight line.

7. The improved method for high-speed dispensing according to claim 1, characterized in that: When the viscosity of the glue is greater than 1000 milliPascal seconds, the reverse inlet (3) and the forward inlet (4) of the Tesla valve are connected in a straight line to the straight pipe (2).

Images