JP7489097B2 - Multi-liquid mixing and dispensing device - Google Patents

Description

The present invention relates to a multi-liquid mixing and discharging device that mixes and discharges multiple fluids.

Conventionally, there are devices that mix multiple fluids internally and then discharge them, such as a two-component adhesive consisting of a base agent and a hardener, as in the two-component adhesive discharge device disclosed in Patent Document 1 below. The two-component adhesive discharge device in Patent Document 1 below has a brass nozzle inserted into the tip of a nylon frame, and a polypropylene mixing unit and a brass inner cylinder inserted alternately into the frame. In addition, this two-component adhesive discharge device has a static mixer sandwiched between holder blocks arranged above and below, and the static mixer is fitted into a recess provided on the opposing surface of the holder block, and the holder block is tightened with a bolt to sandwich the static mixer between the holders.

Japanese Patent Application Laid-Open No. 5-31426

In a multi-liquid mixing and dispensing device such as the two-liquid mixing adhesive dispensing device described above, if the densities (specific gravities) of the liquids to be mixed are different, there is a concern that a phenomenon in which a fluid with a higher density is replaced by a fluid with a lower density (hereinafter also referred to as "liquid displacement") may occur, for example, when the dispensing of the liquid is stopped and left alone during a downtime. If liquid displacement occurs, one liquid used for mixing may get into a pipe for supplying another liquid, which may cause problems such as, for example, reactions in places where maintenance such as cleaning is difficult to perform, or in places where the liquids should not react with each other.

Therefore, the present invention aims to provide a multi-liquid mixing and dispensing device that can minimize the occurrence of liquid replacement.

(1) The multi-liquid mixing and discharging device of the present invention mixes and discharges at least a first fluid and a second fluid having a lower density than the first fluid, and is characterized by comprising a first flow path for transporting the first fluid, a second flow path for transporting the second fluid, a mixing unit for mixing the first fluid transported by the first flow path and the second fluid transported by the second flow path, and an infiltration suppression section for suppressing at least one of the infiltration of the second fluid into the first flow path and the infiltration of the first fluid into the second flow path.

The multi-liquid mixing and discharging device of the present invention can mix a first fluid and a second fluid in a mixing unit to which a first flow path and a second flow path are connected. In addition, the multi-liquid mixing and discharging device of the present invention is equipped with an infiltration suppression section, and is configured to suppress at least one of the infiltration of the second fluid into the first flow path and the infiltration of the first fluid into the second flow path. Therefore, the multi-liquid mixing and discharging device of the present invention can suppress the occurrence of liquid replacement caused by the replacement of the fluid with the greater density of the first fluid or the second fluid with the fluid with the lesser density.

(2) The above-mentioned multi-liquid mixing and discharging device is preferably characterized in that the mixing unit includes a confluence section where the first flow path and the second flow path join, and a mixer section, and the infiltration suppression section is provided near the end of the first flow path, near the end of the second flow path, the confluence section, or the mixer section.

This configuration makes it possible to prevent problems caused by contact between the first and second fluids in locations where contact between the first and second fluids is expected, such as near the end of the first flow path, near the end of the second flow path, the junction, and the mixer.

(3) The above-mentioned multi-liquid mixing and discharging device may be characterized in that the infiltration suppression part is detachable.

This configuration makes it possible to provide a multi-liquid mixing and discharging device that can perform maintenance by attaching and detaching the infiltration suppression unit, even if the first fluid and the second fluid are mixed at the location where the infiltration suppression unit is provided.

(4) The above-mentioned multi-liquid mixing and discharging device may be characterized in that the infiltration suppression section has one or more openings having a cross-sectional area smaller than the cross-sectional area of the first flow path or the second flow path.

This configuration can further reduce the possibility of fluid flowing from one of the first flow path and the second flow path to the other due to the action of interfacial tension and the resistance to fluid flow at the opening. This can further improve the effect of suppressing liquid replacement by providing the infiltration suppression section.

(5) The above-mentioned multi-liquid mixing and discharging device is preferably characterized in that the infiltration suppression part has a part formed in any one of the following shapes: a mesh shape, a lattice shape, a perforated plate shape having multiple holes, or a porous shape through which liquid can pass.

With this configuration, the action of interfacial tension in the infiltration suppression section can further reduce the possibility of fluid flowing from one of the first flow path and the second flow path to the other. Therefore, by configuring the infiltration suppression section as described above, the occurrence of liquid replacement can be more reliably suppressed.

(6) In the above-mentioned multi-liquid mixing and discharging device, the infiltration suppression section may be characterized by having pores that can generate a force, by at least one of interfacial tension and pipeline resistance, that resists the infiltration of one of the first and second fluids into a flow path for transporting the other fluid.

With this configuration, the opposing forces of interfacial tension and pipeline resistance that occur in the pores of the infiltration suppression section act to resist the inflow of fluid from one of the first flow path and the second flow path to the other, further suppressing the occurrence of liquid replacement.

(7) The above-mentioned multi-liquid mixing and discharging device may be characterized in that the infiltration suppression section is provided with a non-return structure in one or both of the first flow path and the second flow path that allows the flow of fluid in the discharge direction and suppresses the flow in the opposite direction.

With this configuration, the non-return structure of the infiltration suppression section can prevent fluid from flowing from one of the first flow path and the second flow path to the other, which would cause liquid replacement.

(8) The above-mentioned multi-liquid mixing and discharging device may further include a single-shaft eccentric screw pump as a fluid supply device for transporting the first fluid and the second fluid to the mixing unit.

According to this configuration, the occurrence of liquid replacement can be more reliably suppressed by utilizing the discharge control ability of the single-shaft eccentric screw pump. Specifically, the single-shaft eccentric screw pump can not only transport the fluid in the discharge direction, but also accurately perform the operation of pulling back the fluid in the opposite direction to the discharge direction (suck back) by switching the rotation direction of the rotor. This makes it possible to discharge the fluid without causing dripping, and to perform suck back to the extent that the fluid does not go beyond the infiltration suppression section and is pulled back from one side of the flow path to the other side of the flow path. Therefore, according to the above-mentioned configuration, the occurrence of liquid replacement can be more reliably suppressed by utilizing the discharge control ability of the single-shaft eccentric screw pump.

The present invention provides a multi-liquid mixing and dispensing device that can minimize the occurrence of liquid replacement.

1 is a cross-sectional view showing a part of a configuration of a multi-liquid mixing and discharging device according to an embodiment of the present invention. 2 is an enlarged cross-sectional view of a main part of the multi-liquid mixing and discharging device of FIG. 1. 2 is a cross-sectional view showing a part of a fluid supplying device included in the multi-liquid mixing and discharging device of FIG. 1 . FIG. 11 is an enlarged cross-sectional view of a main part of a multi-liquid mixture discharge device according to a first modified example. FIG. 11 is an enlarged cross-sectional view of a main part of a multi-liquid mixing and discharging device according to a second modified example. FIG. 11 is an enlarged cross-sectional view of a main part of a multi-liquid mixing and discharging device according to a third modified example. FIG. 13 is an enlarged cross-sectional view of a main part of a multi-liquid mixture discharge device according to a fourth modified example. FIG. 13 is an enlarged cross-sectional view of a main part of a multiple liquid mixing and discharging device according to a fifth modified example. FIG. 13 is an enlarged cross-sectional view of a main part of a multiple liquid mixing and discharging device according to a sixth modified example. FIG. 13 is an enlarged cross-sectional view of a main part of a multi-liquid mixture discharge device according to a seventh modified example. 6A and 6B are schematic diagrams showing the state of a fluid in an opening formed in the infiltration suppression portion. 6A and 6B are schematic diagrams showing the state of a fluid in an opening formed in the infiltration suppression portion.

The following describes in detail a multi-liquid mixing and discharging device 10 according to one embodiment of the present invention with reference to the drawings. In the following description, the configuration of the multi-liquid mixing and discharging device 10 will be described first, and then the operation of the multi-liquid mixing and discharging device 10 will be described.

<Configuration of multi-liquid mixing and discharging device 10>
The multi-liquid mixing and discharging device 10 mixes and discharges multiple fluids, such as a two-liquid adhesive consisting of a base agent and a curing agent. The multi-liquid mixing and discharging device 10 of this embodiment is a device that mixes and discharges two types of fluids consisting of a first fluid and a second fluid having a lower density than the first fluid. As shown in FIG. 1, the multi-liquid mixing and discharging device 10 of this embodiment is configured on the premise that the first fluid has a higher density than the second fluid. The multi-liquid mixing and discharging device 10 includes a first flow path 20, a second flow path 30, a mixing unit 40, an infiltration suppression unit 50, and a fluid supply device 60.

The first flow path 20 is a flow path that transports a first fluid. The second flow path 30 is a flow path that transports a second fluid. The first flow path 20 and the second flow path 30 are each capable of transporting fluids from above to below. As shown in FIG. 2, the first flow path 20 and the second flow path 30 have a first external flow path 20a and a second external flow path 30a that are arranged outside the junction 43, which will be described in detail later, and a first internal flow path 20b and a second internal flow path 30b that are arranged inside the junction 43.

As shown in FIG. 4, the mixing unit 40 has the above-mentioned first internal flow path 20b and second internal flow path 30b arranged inside the confluence section 43, a confluence flow path 45 provided at the terminal ends of both flow paths, and a mixer section 42 provided.

Specifically, the junction 43 is made of a hollow member having an internal space, and the first external flow path 20a and the second external flow path 30a are connected from the top surface 43a side. Inside the junction 43, the first flow path 20 and the second flow path 30 are arranged so that the parts forming the first internal flow path 20b and the second internal flow path 30b reach the bottom surface 43b. When the first external flow path 20a is connected from the top surface 40a side of the junction 43, the first external flow path 20a and the first internal flow path 20b are connected, and the first flow path 20 is formed as a series of flow paths. Similarly, when the second external flow path 30a is connected from the top surface 40a side, the second external flow path 30a and the second internal flow path 30b are connected, and the second flow path 30 is formed as a series of flow paths. The first flow path 20 and the second flow path 30 are joined at the parts forming the first internal flow path 20b and the second internal flow path 30b in the junction 43.

More specifically, inside the confluence section 43, a confluence flow path 45 is provided at the end side of the second flow path 30 (second internal flow path 30b). The confluence flow path 45 has a flow path diameter larger than the flow path diameter of the second flow path 30 upstream of the confluence flow path 45. In addition, the first flow path 20 (first internal flow path 20b) is formed so as to reach the bottom surface 43b side from the top surface 43a side of the confluence section 43. The first flow path 20 is inserted into the axial center position of the confluence flow path 45 at the end side. Therefore, the confluence flow path 45 has a double pipe structure with the first flow path 20 as the inner pipe and the second flow path 30 as the outer pipe. As a result, the first flow path 20 and the second flow path 30 are confluent at the confluence flow path 45 at their respective end portions. Therefore, the first fluid transported by the first flow path 20 confluences with the second fluid transported by the second flow path 30 at the confluence flow path 45 and comes into contact with each other.

The mixer section 42 is composed of, for example, a static mixer, a dynamic mixer equipped with a drive screw that operates by receiving power from a drive source such as a motor, etc. In this embodiment, the mixer section 42 is composed of a static mixer. Specifically, the mixer section 42 has a mixer casing 42a and an element 42b. The mixer casing 42a houses the element 42b. The mixer casing 42a is provided on the bottom surface 43b side of the confluence section 43 so as to communicate with the confluence flow path 45. The element 42b mixes the first fluid and the second fluid that have merged in the confluence flow path 45 and flowed into the mixer casing 42a. The element 42b is composed of alternating right-twisted or left-twisted spiral plates, and can mix and stir the passing fluids approximately uniformly. The mixer section 42 is detachable from the casing of the confluence section 43 so that it can be replaced or removed for use, for example, during maintenance work such as cleaning, or depending on the application.

The infiltration suppression section 50 is provided to suppress infiltration of one of the first and second fluids, which have different densities, into a flow path (the first flow path 20 or the second flow path 30) for transporting the other fluid.

Here, in this embodiment, the first flow path 20 and the second flow path 30 are assumed to transport the first fluid and the second fluid from above to below. The density of the first fluid is assumed to be greater than the density of the second fluid. Therefore, when the flow of the first fluid and the second fluid stops during a period when the multi-liquid mixing and discharging device 10 is not in operation, the first fluid having a higher density may descend in the merging flow path 45, and the second fluid having a lower density may ascend. If such a phenomenon occurs, there is a concern that the second fluid having a lower density may infiltrate from the end portion of the first flow path 20 for transporting the first fluid having a higher density, causing liquid replacement. Therefore, in the multi-liquid mixing and discharging device 10, an infiltration suppression section 50 is arranged to prevent the second fluid from infiltrating from the end portion of the first flow path 20.

The infiltration suppression unit 50 is inserted into the terminal portion of the first flow path 20. The infiltration suppression unit 50 is detachable from the first flow path 20. The infiltration suppression unit 50 is cylindrical and has an outer diameter that approximately matches the inner diameter of the pipe that forms the first flow path 20. The infiltration suppression unit 50 has a pore 52 located approximately at the axial center.

The pore 52 is a hole having an opening cross-sectional area that is significantly smaller than the flow path cross-sectional area of the first flow path 20. The pore 52 has a substantially circular cross-section like the piping that constitutes the first flow path 20, and is significantly reduced in diameter compared to the inner diameter of the first flow path 20. The size of the opening area and the passage length (the vertical length in the illustrated state) of the pore 52 are specified so that the pore 52 has an interfacial tension and pipeline resistance that counteract the force with which the second fluid penetrates the first flow path 20 in the discharge stop state.

The size of the opening area and the passage length of the pores 52 may be set based on experiments, various simulations, logical methods, etc. Furthermore, when the size of the opening area and the passage length of the pores 52 are set based on simulations, logical methods, etc., they may be set by a method such as deriving based on a predetermined logical formula, etc., taking into consideration the properties of the fluids used (first fluid, second fluid) such as viscosity and density, the mixing ratio of the fluids, the flow rate, the discharge pressure, etc. Furthermore, when the first fluid or the second fluid contains fine particles such as a slurry or a filler, the size of the opening area of the pores 52 may be specified so that clogging does not occur.

The fluid supply device 60 is a device for supplying the first fluid and the second fluid toward the junction 43 via the first flow path 20 and the second flow path 30. As shown in FIG. 1, the fluid supply device 60 is provided in each of the first flow path 20 and the second flow path 30. For example, a conventionally known rotary volumetric pump, a plunger pump, an air pressurized pump, or the like can be used for the fluid supply device 60. In consideration of the fluid discharge control ability, etc., it is preferable that the fluid supply device 60 is configured by a single-shaft eccentric screw pump.

Specifically, as shown in FIG. 3, the fluid supply device 60 is configured to house a rotor 102, a stator 104, a power transmission mechanism 106, etc., inside a casing 100. The casing 100 is a metallic cylindrical member, and is provided with a first opening 110 at one end in the longitudinal direction. In addition, a second opening 112 is provided on the outer periphery of the casing 100. The second opening 112 is connected to the internal space of the casing 100 at an intermediate portion 114 located in the longitudinal middle portion of the casing 100.

The first opening 110 and the second opening 112 are parts that function as the suction port and the discharge port, respectively, of the uniaxial eccentric screw pump that constitutes the fluid supply device 60. The fluid supply device 60 can make the first opening 110 function as the discharge port and the second opening 112 function as the suction port by rotating the rotor 102 in the forward direction. Also, the first opening 110 can be made to function as the suction port and the second opening 112 as the discharge port by rotating the rotor 102 in the reverse direction.

The stator 104 is a member having a generally cylindrical exterior shape formed from an elastic body such as rubber, or from a resin, etc. The inner peripheral wall 116 of the stator 104 has an n-thread single-stage or multi-stage female thread shape. In this embodiment, the stator 104 has a two-thread multi-stage female thread shape. In addition, the through-hole 118 of the stator 104 is formed so that its cross-sectional shape (opening shape) is generally elliptical when viewed in cross section at any position in the longitudinal direction of the stator 104.

The rotor 102 is a metallic shaft body, and has a single-stage or multi-stage male thread with n-1 threads. In this embodiment, the rotor 102 has a single-stage eccentric male thread. The rotor 102 is formed so that its cross-sectional shape is a nearly perfect circle when viewed in cross section at any position in the longitudinal direction. The rotor 102 is inserted into the through-hole 118 formed in the stator 104 described above, and is free to rotate eccentrically inside the through-hole 118.

When the rotor 102 is inserted into the stator 104, the outer peripheral wall 120 of the rotor 102 and the inner peripheral wall 116 of the stator 104 are in close contact with each other at their tangents. This forms a fluid transport path 122 (cavity) between the inner peripheral wall 116 of the stator 104 and the outer peripheral wall 120 of the rotor 102. The fluid transport path 122 extends in a spiral shape in the longitudinal direction of the stator 104 and the rotor 102.

When the rotor 102 is rotated in the through hole 118 of the stator 104, the fluid transport path 122 advances in the longitudinal direction of the stator 104 while rotating within the stator 104. Therefore, when the rotor 102 is rotated, the fluid is sucked into the fluid transport path 122 from one end side of the stator 104, and the fluid is transported toward the other end side of the stator 104 while being confined within the fluid transport path 122, and can be discharged at the other end side of the stator 104. Specifically, when the rotor 102 is rotated forward, an operation of sucking in a fluid from the second opening 112 and discharging it from the first opening 110 (discharge operation) can be performed. In addition, by rotating the rotor 102 in the reverse direction, an operation of sucking in a fluid in the opposite direction to the discharge operation, that is, from the first opening 110 side toward the second opening 112 side (pull-back operation) can be performed.

The power transmission mechanism 106 is for transmitting power from the driving machine 124 to the rotor 102 described above. The power transmission mechanism 106 has a power transmission section 126 and an eccentric rotation section 128. The power transmission section 126 is provided at one end side of the longitudinal direction of the casing 100. The eccentric rotation section 128 is provided at the intermediate section 114. The eccentric rotation section 128 is a section that connects the power transmission section 126 and the rotor 102 so that power can be transmitted. The eccentric rotation section 128 is provided with a connecting shaft 130 that is formed of a conventionally known coupling rod, flexible shaft, or the like. Therefore, the eccentric rotation section 128 can transmit the rotational power generated by operating the driving machine 124 to the rotor 102 and rotate the rotor 102 eccentrically.

As described above, the multi-liquid mixing and discharging device 10 of this embodiment can merge and mix the first and second fluids in the merging flow path 45 provided in the merging section 43 to which the first flow path 20 and the second flow path 30 are connected. In addition, the multi-liquid mixing and discharging device 10 is equipped with an infiltration suppression section 50. This can suppress the infiltration of the second fluid into the first flow path 20 even when the flows of the first and second fluids are stopped, such as during a period when the multi-liquid mixing and discharging device 10 is out of operation. Therefore, the multi-liquid mixing and discharging device 10 can suppress the occurrence of liquid replacement caused by the replacement of the fluid with the higher density of the first and second fluids (the first fluid in this embodiment) with the fluid with the lower density (the second fluid in this embodiment).

As described above, the infiltration suppression unit 50 of the multi-liquid mixing and discharging device 10 can be attached and detached by means of screws, fitting, or other means not shown. Therefore, the infiltration suppression unit 50 of the multi-liquid mixing and discharging device 10 can be attached and detached as necessary for maintenance, etc.

As described above, the multi-liquid mixing and discharging device 10 is equipped with a single-shaft eccentric screw pump as the fluid supply device 60 for transporting the first fluid and the second fluid to the junction 43. The single-shaft eccentric screw pump constituting the fluid supply device 60 has excellent characteristics in terms of fluid discharge control ability. Specifically, the fluid supply device 60 can precisely perform not only the operation of transporting the first fluid and the second fluid in the discharge direction, but also the operation of pulling back (sucking back) in the opposite direction to the discharge direction by switching the rotation direction of the rotor 102. This allows the first fluid and the second fluid to be discharged without causing dripping at the end of the first flow path 20 or the second flow path 30, and sucking back to the extent that the fluid is not pulled back from one side of the first flow path 20 or the second flow path 30 to the other side beyond the infiltration suppression unit 50. Therefore, the multi-liquid mixing and discharging device 10 can reliably suppress the occurrence of liquid replacement due to the synergistic effect of the liquid replacement suppression effect of the infiltration suppression unit 50 and the fluid discharge control ability of the single-shaft eccentric screw pump.

In this embodiment, the fluid supply device 60 consisting of a single-shaft eccentric screw pump is connected to both the first flow path 20 and the second flow path 30, but the present invention is not limited to this. Specifically, depending on various conditions, such as not requiring high-precision discharge control capabilities such as a single-shaft eccentric screw pump, the multi-liquid mixing and discharging device 10 may be provided with a pump other than the single-shaft eccentric screw pump as the fluid supply device 60 for one or both of the first flow path 20 and the second flow path 30.

As described above, the infiltration suppression unit 50 has pores 52 (openings) with an opening cross-sectional area smaller than the cross-sectional area of the first flow path 20 or the second flow path 30. Therefore, the infiltration suppression unit 50 can suppress the inflow of fluid from one of the first flow path 20 and the second flow path 30 to the other due to the action of the fluid passage resistance and interfacial tension in the pores 52. Therefore, the above-mentioned multi-liquid mixing and discharge device 10 can be expected to have a high liquid replacement suppression effect due to the infiltration suppression unit 50.

The pores 52 provided in the infiltration suppression unit 50 described above have an interfacial tension and pipeline resistance that counteract the force of one of the first and second fluids (the second fluid in this embodiment) infiltrating into the flow path (the first flow path 20 in this embodiment) for transporting the other fluid (the first fluid in this embodiment) when discharge is stopped. Therefore, the infiltration suppression unit 50 can further suppress the possibility of liquid replacement occurring due to the action of the interfacial tension and pipeline resistance of the pores 52.

In the present embodiment, the infiltration suppression unit 50 is exemplified by providing one pore 52 at the axial center position, but the present invention is not limited to this. For example, in cases where it is necessary to consider conditions such as the discharge amount of the first fluid required in the first flow path 20 and the discharge position, the infiltration suppression unit 50 may be provided with an opening similar to the pore 52 at a position away from the axial center position, or with multiple openings similar to the pore 52 at the axial center position or other locations.

In this embodiment, the infiltration suppression unit 50 is exemplified as having a fine hole 52, but the present invention is not limited to this. For example, as shown in FIG. 4, an infiltration suppression unit 150 having a check structure 152 may be provided instead of the infiltration suppression unit 50. The check structure 152 is provided with a structure that allows the flow of fluid in the direction in which the first fluid is discharged from the first flow path 20 and suppresses the flow in the opposite direction. The check structure 152 in the illustrated example is provided with a check valve 154 formed of a flexible material such as rubber. Even when such an infiltration suppression unit 150 is used, it is possible to suppress the fluid from flowing from one of the first flow path 20 and the second flow path 30 to the other, which causes liquid replacement, in the same way as when the infiltration suppression unit 50 is provided.

As shown in FIG. 5, the multi-liquid mixing and discharging device 10 may be provided with an infiltration suppression unit 250 instead of the infiltration suppression unit 50. The infiltration suppression unit 250 has a mesh unit 252 attached to the opening area at the end of the first flow path 20. The mesh unit 252 has a mesh shape with a large number of meshes whose opening area is significantly smaller than the opening cross-sectional area of the first flow path 20. Even when such an infiltration suppression unit 250 is provided, it is possible to suppress the second fluid from infiltrating the first flow path 20 due to the action of interfacial tension, etc., and causing liquid replacement, as in the case where the infiltration suppression unit 50 is provided.

In FIG. 5, an example is shown in which a mesh-shaped infiltration suppression section 250 is used, but the infiltration suppression section 250 may be lattice-shaped or a perforated plate-shaped section having multiple holes. Even when the infiltration suppression section 250 is lattice-shaped or a perforated plate-shaped section having multiple holes, the size of each opening area is made significantly smaller than the cross-sectional area of the opening of the first flow path 20, so that the second fluid can be prevented from infiltrating the first flow path 20 due to the action of interfacial tension, etc., and causing liquid replacement.

As shown in FIG. 6, the multi-liquid mixing discharge device 10 may be provided with an infiltration suppression section 350 instead of the infiltration suppression section 50. The infiltration suppression section 350 is not flat like the infiltration suppression section 250 described above, but is three-dimensional like a sponge, and has a porous section 352 with a porous shape having many holes through which the fluid can pass. The porous section 352 is inserted from the end of the first flow path 20 toward the upstream side. When such an infiltration suppression section 350 is provided, it is possible to suppress the second fluid from infiltrating the first flow path 20 and causing liquid replacement, as in the case of providing the infiltration suppression section 50 or the infiltration suppression section 150.

The above-mentioned multi-liquid mixing and discharging device 10 has a double-tube-shaped portion at the end of the first flow path 20 and the second flow path 30, in which the piping constituting both flow paths is arranged so that the axial center positions are approximately aligned, and a confluence flow path 45 is provided downstream of the double-tube-shaped portion, but the present invention is not limited to this. For example, as shown in FIG. 7, a space 432 may be provided inside the confluence portion 43, and the first flow path 20 and the second flow path 30 may be connected to this space 432 separately. In addition, in such a configuration, it is preferable to provide the above-mentioned infiltration suppression portion 50, 150, 250, 350, etc. at the end of either one or both of the first flow path 20 and the second flow path 30. In the illustrated example, a mesh-shaped infiltration suppression portion 250 is provided at the end of the first flow path 20. Even in such a configuration, the occurrence of liquid replacement can be suppressed in the same way as in the above-mentioned embodiment and modified example.

The above-mentioned multi-liquid mixing and discharging device 10 is provided with an infiltration suppression section 50, 150, 250, 350 at the end of either the first flow path 20 or the second flow path 30 (first flow path 20 in the above-mentioned example), but the present invention is not limited to this. For example, as shown in FIG. 8, a configuration may be used in which an infiltration suppression section 450 having a mesh section 452 is provided at the end of both the first flow path 20 and the second flow path 30 arranged in parallel. The mesh section 452 is made of a mesh-like material, similar to the mesh section 252 described above. The multi-liquid mixing and discharging device 10 can also suppress the occurrence of liquid replacement by being configured in this way.

In the example of FIG. 8, the infiltration suppression section 450 is provided with a mesh section 452, but the multi-liquid mixing and discharging device 10 may be provided with, for example, the pores 52 of the infiltration suppression section 50 at positions corresponding to the first flow path 20 and the second flow path 30. The multi-liquid mixing and discharging device 10 may also be configured to provide a check structure 152 or a porous section 352 in each of the first flow path 20 and the second flow path 30. Furthermore, the multi-liquid mixing and discharging device 10 may be provided with an appropriate combination of infiltration suppression functions such as pores 52, check structure 152, mesh section 252, and porous section 352 in the first flow path 20 and the second flow path 30 (for example, pores 52 in the first flow path 20, porous section 352 in the second flow path 30, etc.). Furthermore, both or either of the first flow path 20 and the second flow path 30 may be provided with a combination of multiple components that exhibit the infiltration suppression function described above (for example, the first flow path 20 may be provided with both a check structure 152 and a mesh portion 252).

In the above-described embodiment and modified example, a configuration is illustrated that assumes that the first fluid supplied to the first flow path 20 has a higher density than the second fluid supplied to the second flow path 30, but the present invention is not limited to this. Specifically, when the first fluid has a lower density than the second fluid, the arrangement of the infiltration suppression units 50, 150, 250, 350, and 450 described above can be reversed, that is, the infiltration suppression unit provided in the first flow path 20 can be provided in the second flow path 30, and the infiltration suppression unit provided in the second flow path 30 can be provided in the first flow path.

In addition, in the above-mentioned embodiment and modified example, the multi-liquid mixing and discharging device 10 is exemplified as supplying the first fluid and the second fluid in the direction of gravity (from top to bottom in the figure), but the present invention is not limited to this. For example, as shown in FIG. 9, the first fluid and the second fluid may be supplied in the opposite direction to the direction of gravity (from bottom to top in the figure). In the case of such a configuration, if the first fluid has a higher density than the second fluid supplied to the second flow path 30, the second fluid with a lower density will rise due to the influence of buoyancy. As a result, contrary to the case of the above-mentioned embodiment, etc., liquid replacement may occur at the end of the second flow path 30 that supplies the second fluid. Therefore, in such a case, the occurrence of liquid replacement can be suppressed by providing the infiltration suppression section 50, 150, 250, 350, 450 at the end of the second flow path 30 as shown in FIG. 9.

The multi-liquid mixing and discharging device 10 exemplified in the above-mentioned embodiment and modified example has been shown to employ a mixer section 42 consisting of a static mixer, but for example, as shown in FIG. 10, a mixer section 542 consisting of a dynamic mixer may be provided in the confluence section 43. The mixer section 542 is provided with an agitating member 546, for example, in a screw shape, inside the agitating chamber 544, and the agitating member 546 is operated by a driving source 548 such as a motor. In addition, for example, as shown in FIG. 10, when the first flow path 20 and the second flow path 30 are connected horizontally to the agitating chamber 544, liquid replacement may occur in both the first flow path 20 and the second flow path 30. Therefore, in such a case, it is preferable to provide one or more of the infiltration suppression sections 50, 150, 250, 350, and 450 (infiltration suppression section 250 in the illustrated example) at the ends of the first flow path 20 and the second flow path 30 connected horizontally. In addition, the infiltration suppression section 250 may be configured to be detachable from the confluence section 43 together with the stirring chamber 544 and the stirring member 546.

Next, one embodiment of a method for determining the size of the holes and openings to be formed in the infiltration suppression units 50, 150, 250, 350, 450, etc. (hereinafter also referred to as "infiltration suppression units 50, etc.") described above, taking into consideration discharge conditions such as the characteristics of the fluid used, and conditions such as the size and shape of the first flow path 20, the second flow path 30, the merging flow path 45, and the mixer unit 42, etc., will be described in detail below.

The size of the holes or openings formed in the infiltration suppression portion 50 etc. may be determined by the following steps (1) to (4).
(1) The discharge conditions are determined based on the characteristics of the fluids used (fluid viscosity, fluid density difference, etc.), the mixture ratio of the first fluid and the second fluid, the desired flow rate, the discharge pressure, etc.
(2) Based on the discharge conditions determined by (1), the diameter and length of the first flow path 20 and the second flow path 30 that transport the first fluid and the second fluid, the shape of the confluence flow path 45, the mixer section 42, etc. are determined, and the pressure loss ΔP that occurs when the liquid passes through the first flow path 20 or the second flow path 30 is derived.
(3) The surface tensions of the first fluid and the second fluid, the contact angles between the first fluid and the second fluid and the material constituting the infiltration suppression portion 50, and the interfacial tension between the first fluid and the second fluid are derived.
(4) Design the size of the opening of the infiltration suppression section 50.

Here, the pressure loss ΔP in the above (2) may be derived based on, for example, the following Darcy-Weisbach (Equation 1).

In the above (3), the surface tension of the first fluid and the second fluid may be derived, for example, by measurement using a surface tensiometer. The contact angles between the first fluid and the second fluid and the material constituting the infiltration suppression section 50, etc. may be derived, for example, by measurement using a contact angle meter. The interfacial tension of the first fluid and the second fluid may be derived, for example, by measurement using an interfacial tensiometer using the drop volume method.

The size of the opening of the infiltration suppression unit 50 etc. in (4) above may be derived, for example, as follows. In the following, in order to simplify the explanation, it is assumed that the opening shape of the infiltration suppression unit 50 etc. is a perfect circle, but this does not exclude, for example, a polygonal shape or an elliptical shape as the opening shape of the infiltration suppression unit 50 etc.

Assuming that the force that the first fluid, the second fluid, and other fluids try to separate due to buoyancy is F1 as a premise for deriving the size of the opening of the infiltration suppression unit 50, etc., above, if the force that tries to stop the movement of the fluid due to the liquid replacement exceeds F1, the liquid replacement will not occur, and even if it cannot be exceeded, if it is large enough, the liquid replacement can be suppressed to a practically sufficient degree. On the other hand, considering minimizing the effect on the discharge of the first fluid and the second fluid, it is preferable that the force that tries to stop the movement of the fluid due to the liquid replacement does not exceed the above-mentioned force F1 too much. In addition, two types of forces are assumed to be involved in the force that tries to stop the liquid replacement: force F2 derived from the interfacial tension of the fluid and force F3 derived from the pipeline resistance. Therefore, it is preferable to design the infiltration suppression unit 50, etc. so that the force F2 derived from the interfacial tension of the fluid and force F3 derived from the pipeline resistance are balanced against the buoyancy force F1 of the fluid.

Here, assuming a mixing section shape in which the liquid with the lower density (the second fluid in the above embodiment) is located lower in the weight direction than any of the infiltration suppression sections 50, 150, 250, 350, 450 (in the illustrated example, infiltration suppression section 250), as shown in the model diagram of Figure 11, the buoyancy F1 of the fluid is expressed by the following (Equation 2).

In the above formula (2), V means the volume of the part where the contact part of one fluid in the initial state in the model diagram of FIG. 11 exceeds the opening area of the infiltration suppression part 50, etc. and becomes convex toward the other fluid. Also, ρH means the density of the fluid with the higher density, ρL means the density of the liquid with the lower density, and g means the acceleration of gravity.

The force F2 that tries to stop the liquid replacement due to the interfacial tension of the fluids is determined by the product of the interfacial tension σi generated between the two types of fluids (the first fluid and the second fluid) and the material of the material constituting the infiltration suppression unit 50, etc., and the circumference (perimeter in the case of a polygonal hole) of the opening provided in the infiltration suppression unit 50. Therefore, the magnitude of the force F2 is determined by the following (Equation 3).

γＬ１ ：第一流体の表面張力
γＬ２ ：第二流体の表面張力
γＬ１２：第一流体と第二流体との界面張力
θ１ ：第一流体と浸入抑制部５０等の材質との接触角
θ２ ：第二流体と浸入抑制部５０等の材質との接触角
θ１２ ：第一流体と第二流体との接触角（γＬ１２から算出可能） The above-mentioned interfacial tension σi can be calculated by the following (Equation 4), which is a modification of Young's equation.

γL1: Surface tension of the first fluid γL2: Surface tension of the second fluid γL12: Interfacial tension between the first fluid and the second fluid θ1: Contact angle between the first fluid and the material of the infiltration suppression part 50, etc. θ2: Contact angle between the second fluid and the material of the infiltration suppression part 50, etc. θ12: Contact angle between the first fluid and the second fluid (can be calculated from γL12)

Furthermore, the force F3 resisting the buoyancy resulting from the pipeline resistance can be derived based on the following (Equation 5) using the Darcy-Weisbach equation.

As described above, the force F2 resulting from interfacial tension and the force F3 resulting from pipeline resistance change depending on the flow path length l and the opening diameter d of the infiltration suppression unit 50, etc., so by appropriately specifying the flow path length l and the opening diameter d, it is possible to realize an infiltration suppression unit 50, etc., that can suppress liquid replacement.

Next, the relationship between the forces acting when the infiltration suppression section 50 with pores 52 and the mesh-shaped infiltration suppression section 250 are provided, and an example of the design concept of the infiltration suppression section 50 and the infiltration suppression section 250 will be described in detail with reference to the drawings. Note that in the description of Example 2, parts that overlap with the description of Example 1 above will be described with the same reference numerals, and detailed description will be omitted.

The force F1 that causes the first fluid, second fluid, and other fluids to separate due to buoyancy can be derived from the above (Formula 2). In addition, the force F2 that causes the interfacial tension of the fluids to stop the liquid replacement can be derived from the above (Formula 3), and the force F3 that causes the piping resistance to stop the liquid replacement can be derived based on the above (Formula 5).

Here, as a state in which liquid replacement can be suppressed, there are two possible states: a state in which liquid replacement is completely suppressed only by interfacial tension as shown in FIG. 12(a) (state 1), and a state in which liquid replacement cannot be stopped but is slowed down by interfacial tension and piping resistance as shown in FIG. 12(b) (state 2). In the state of FIG. 12(a), the force relationship is F1≦F2. In addition, in the state of FIG. 12(b), the force relationship is F1>F2+F3. In addition, if no movement occurs in the fluid, the deceleration effect by the above-mentioned force F3 is considered to be ineffective. The infiltration suppression part 250, which is mesh-shaped, tends to easily maintain (state 1), and the infiltration suppression part 50 with the pores 52 tends to easily maintain (state 2). In addition, in the state of FIG. 12(b), it is possible that a part of the fluid may be cut off and a part (droplet) of one fluid may flow into the other fluid side as shown in FIG. 12(c). In the state of FIG. 12(c), the force relationship is F1>F3. By specifying the size of the opening and the length of the flow path of the infiltration suppression unit 50 so that the size of F2+F3 is sufficiently larger than F1, it is possible to prevent the state shown in FIG. 12(c) from occurring and to suppress the size of the infiltrating droplets.

Here, we compare a capillary type with pores 52, such as the infiltration suppression unit 50 described above, with a mesh type with many openings, such as the infiltration suppression unit 250, and consider the forces acting near the infiltration suppression units 50 and 250.

First, assume that the fluid on one side is about to infiltrate through the infiltration suppression unit 50, 250 toward the liquid on the other side. In this case, the volume V of the convex portion (hereinafter also referred to as the "convex portion 254") in the fluid that is about to infiltrate beyond the infiltration suppression unit 50, 250 is n% (n < 100) of the cube of the diameter d of the opening formed in the infiltration suppression unit 50, 250. Therefore, when focusing on one hole formed in the infiltration suppression unit 50, 250, the ratio of the circumference of the hole to the volume V of the convex portion 254 of the fluid tends to be smaller as the diameter of the opening becomes smaller. Therefore, the smaller the opening hole formed in the infiltration suppression unit 50, 250, the more the interfacial tension F2 tends to be stronger than the force F1 that tries to separate due to buoyancy. In addition, the pipeline resistance F3 also shows a tendency for the volume V of the fluid convex portion 254 to be smaller relative to the circumference of the opening hole formed in the infiltration suppression portion 50, 250.

Since the capillary type infiltration suppression unit 50 must also discharge the fluid through one pore 52, there is a limit to how small one pore 52 can be, assuming the total flow rate. However, even if the interfacial tension F2 is smaller than the force F1, if the length of the duct that forms the pore 52 is sufficient, it is possible to slow down the progress of liquid replacement due to the influence of the duct resistance F3. On the other hand, since the mesh type infiltration suppression unit 250 has many openings, even if the size of each opening is small, it is unlikely to cause any obstruction to discharge as a whole. In the mesh type infiltration suppression unit 250, the size of each opening can be made smaller than that of the capillary type infiltration suppression unit 50, so that the interfacial tension F2 can be made relatively large relative to the force F1. Note that in the infiltration suppression unit 250, unlike the infiltration suppression unit 50, it is considered that almost no duct resistance F3 occurs. Therefore, in order to reliably suppress liquid replacement in the infiltration suppression unit 250, it is desirable to adjust the size of the opening so that the interfacial tension F2 is sufficiently large relative to the force F1.

Next, an example of a method for designing the infiltration suppression unit 50, 250 in consideration of the characteristics of the capillary type and the mesh type as described above will be described. First, in the case of the capillary type infiltration suppression unit 50, as described above, if the aim is to make F1≦F2, the size of the opening tends to be so small that a single pore 52 cannot discharge the fluid. Therefore, in the case of the capillary type infiltration suppression unit 50, it is desirable to design it taking into account not only the interfacial tension F2 but also the effect of the pipe resistance F3. That is, in the case of the infiltration suppression unit 50, it is preferable to design it so that the relationship F1>F2+F3 is established and the difference between F1 and (F2+F3) is small. Specifically, in the case of the infiltration suppression unit 50, in the following (Equation 6), even if the flow rate u of the liquid replacement is near 0, the pore 52 with the length l and the diameter d is designed to minimize the difference between the left and right terms.

Furthermore, in the case of the mesh-type infiltration suppression unit 250, as described above, even if the size of each opening is small, the effect on the discharge of the fluid is small. Therefore, it is expected that the liquid replacement will be stopped only by the interfacial tension F2. Since the interfacial tension F2 can be considered for each opening, the volume V of the convex portion 254 can be made relatively small. Therefore, in the case of the mesh-type infiltration suppression unit 250, it is preferable to design it so that F1≦F2 is satisfied. Specifically, the diameter d of the openings that make up the mesh can be specified so as to satisfy the following (Equation 7).

When multiple pores 52 are provided in the infiltration suppression section 50, when multiple infiltration suppression sections 50 each having a single pore 52 are provided in parallel, when a thick infiltration suppression section 250 is used, etc., the design may be based on the above (Formula 6), or it may be designed using (Formula 7) while making the flow path length as long as possible to ensure that the pipeline resistance F3 is used as a factor for ensuring the suppression of liquid replacement.

The following describes the test conducted to verify the effect of providing the infiltration suppression portion 50, 250 described above. In this embodiment, an epoxy-based structural two-component adhesive (TB3950D manufactured by ThreeBond Fine Chemical Co., Ltd.) that bonds by a curing reaction of the main agent and the curing agent was used in the test. The epoxy-based structural two-component adhesive used in this test has the property of curing in 15 minutes by mixing the main agent and the curing agent in a mixing ratio of 1:1. In addition, the main agent used in this embodiment has a specific gravity of 1.18 g/cm ³ and a viscosity of 2.7 Pa·s (25°C), and the curing agent has a specific gravity of 1.00 g/cm ³ and a viscosity of 2.2 Pa·s (25°C).

In this example, an acrylic straight tube with a flow path length of approximately 10 cm and an inner diameter of 3 mm was used as a flow path for transporting a fluid with a high density (corresponding to the first flow path 20 in the above embodiment) among the flow paths connected to the junction 43, and this straight tube was filled with the agent. In addition, a cup with an internal volume of 2 ml was used as the junction flow path 45, and the straight tube was held vertically inside the cup. The cup was filled with the hardener until the bottom end of the straight tube touched the cup, and the progress was observed to reproduce the stopped state of the multi-liquid mixing and discharging device 10. The temperature environment was approximately 25°C in all tests.

First, the above test was conducted without providing anything equivalent to the infiltration suppression unit 50, 250 at the end of the acrylic straight tube. As a result, the top of the hardener filled in the cup, which was used as the merging flow path 45, rose about 1 mm inside the acrylic tube during the period from immediately after the acrylic straight tube filled with the agent was placed in the cup filled with the hardener until about 5 minutes later. However, after 5 minutes had passed, the hardener continued to rise about 8 mm every 5 minutes near the center of the acrylic tube, which is inside the agent. As a result of leaving the acrylic straight tube filled with the agent in the cup for about 4 hours, the hardener penetrated the entire acrylic tube and even mixed to the extent that the hardening reaction proceeded. Therefore, it was confirmed that liquid replacement proceeds over time when something equivalent to the infiltration suppression unit 50, 250 is not provided.

Next, a similar test was performed on the straight acrylic pipe with the capillary-type infiltration suppression section 50 at the end of the pipe. In this embodiment, three types of infiltration suppression sections 50 with different sizes of pores 52 were prepared as samples and tested. Specifically, a test was performed on a first sample with an inner diameter of pores 52 of 2 mm and a length of pores 52 of about 5 mm. From the start of the test until about 30 minutes, small droplets of hardener with a diameter of about 1 mm or less, which did not cause a curing reaction, were generated and rose in the straight acrylic pipe at a rate of about once every 5 minutes. However, after about 30 minutes had passed from the start of the test, the intervals at which such droplets were generated became more gradual. Even when left for about 17 hours from the start of the test, only a dozen or so droplets of hardener had infiltrated into the straight acrylic pipe, which was not enough to cause the straight pipe to be blocked by the curing reaction.

In addition, when a test was conducted on a second sample of the infiltration suppression section 50 in which the inner diameter of the pores 52 was 1 mm and the length of the pores 52 was approximately 5 mm, no liquid replacement was observed even after approximately 6 hours had passed since the start of the test. Approximately 23 hours after the start of the test, a phenomenon was observed in which the hardener rose in a very thin line of approximately 1 cm at the bottom end of the straight acrylic tube, and several droplets of hardener smaller than those in the test for the first sample described above penetrated into the straight acrylic tube, but the hardening reaction was not severe enough to block the straight tube.

In addition, when a test was conducted on a third sample of the infiltration suppression section 50 in which the inner diameter of the pores 52 was 2 mm and the length of the pores 52 was approximately 1 mm, no change was observed until 60 minutes after the start of the test. However, after 60 minutes had passed from the start of the test, the phenomenon of larger droplets of the hardener penetrating into the straight acrylic tube than in the test on the first sample described above occurred frequently, and after 270 minutes, droplets were observed throughout the entire straight tube. About 8 hours after the start of the test, the mixture of the agent and hardener had progressed to a degree that raised the risk of blockage due to a hardening reaction.

From the above results, it was found that by optimizing the size of the pores 52, as in the case of the first and second samples described above, it is possible to suppress the occurrence of liquid replacement, even in cases where the factory is shut down for several hours, for example, at night or for maintenance.

Next, a similar test was conducted on the end of the acrylic straight pipe provided with a mesh-type infiltration suppression section 250. In the test of this embodiment, a nylon mesh sheet with 110 mesh, line diameter 71 μm, opening rate 48%, and thickness 130 μm was used as the mesh constituting the infiltration suppression section 250. When such an infiltration suppression section 250 was provided at the end of the acrylic straight pipe and a similar test was conducted, no liquid replacement phenomenon beyond the mesh was observed even after 160 minutes had passed since the start of the test. In addition, no phenomenon such as gelation due to a hardening reaction on the mesh was observed. From this result, it was discovered that the occurrence of liquid replacement can also be suppressed by providing a mesh-type infiltration suppression section 250.

The present invention is not limited to the above-described embodiments and variations, and other embodiments may be possible within the scope of the claims, based on the teachings and spirit of the invention. The components of the above-described embodiments may be arbitrarily selected and combined. Any component of the embodiment may also be arbitrarily combined with any component described in the means for solving the invention or any component that embodies any component described in the means for solving the invention. We intend to obtain rights to these as well through amendments to this application or divisional applications, etc.

The present invention can be suitably used in general multi-liquid mixing and dispensing devices that dispense fluids that require mixing and dispensing multiple fluids, such as two-liquid adhesives consisting of a base agent and a curing agent.

10: Multi-liquid mixing and discharging device 20: First flow path 30: Second flow path 40: Mixing unit 50: Infiltration suppression section 52: Fine hole 60: Fluid supply device 150: Infiltration suppression section 152: Non-return structure 250: Infiltration suppression section 350: Infiltration suppression section 450: Infiltration suppression section

Claims (7)

A multi-liquid mixing and discharging device that mixes and discharges at least a first fluid and a second fluid having a lower density than the first fluid,
A first flow path that transports the first fluid;
A second flow path for transporting the second fluid;
a mixing unit that mixes the first fluid transferred through the first flow path and the second fluid transferred through the second flow path;
an infiltration suppression unit that suppresses at least one of infiltration of the second fluid into the first flow path and infiltration of the first fluid into the second flow path due to a density difference between the first fluid and the second fluid;
Equipped with
the infiltration suppression portion includes pores that can generate a force, by at least one of interfacial tension and pipeline resistance, against one of the first fluid and the second fluid attempting to infiltrate into a flow path for transporting the other fluid in a discharge stopped state;
The multi-liquid mixing and discharging device is characterized in that the first flow path and the second flow path are constantly in communication with each other via the fine hole . The mixing unit comprises:
a junction portion where the first flow path and the second flow path join;
A mixer unit,
2. The multi-liquid mixing and discharging device according to claim 1, wherein the infiltration suppression section is provided at least in one of the vicinity of a terminal end of the first flow path, the vicinity of a terminal end of the second flow path, the junction section, and the mixer section. The multi-liquid mixing and discharging device according to claim 1 or 2, characterized in that the infiltration suppression part is detachable. The multi-liquid mixing and discharging device according to any one of claims 1 to 3, characterized in that the infiltration suppression section has one or more openings with a cross-sectional area smaller than the cross-sectional area of the first flow path or the second flow path. The multi-liquid mixing and discharging device according to any one of claims 1 to 4, characterized in that the infiltration suppression section has a portion formed in any one of the following shapes: a mesh shape, a lattice shape, a perforated plate shape having multiple holes, or a porous shape through which liquid can pass. The multi-liquid mixing and discharging device according to any one of claims 1 to 5, characterized in that the infiltration suppression section is provided with a check structure in one or both of the first flow path and the second flow path that allows fluid to flow in the discharge direction and suppresses the flow in the reverse direction. 7. The multi-liquid mixing and discharging device according to claim 1 , further comprising a single-shaft eccentric screw pump as a fluid supply device for transporting the first fluid and the second fluid to the mixing unit.

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