Coating liquid mixing device and coating liquid mixing method

Abstract

The object of the present invention is to provide a coating liquid mixing device with excellent maintainability. The coating liquid mixing device comprises: a supply pipe part having a plurality of flow paths for a plurality of coating liquids to flow respectively, the plurality of flow paths opening at the front end side; and a mixing nozzle part connected to the outlet part of the supply pipe part so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, and having a constricted part in which the internal space narrows as it moves toward the outlet side so that the opening area is smaller than the total opening area of ​​the plurality of flow paths.

Description

Technical Field

[0001] The present invention relates to a technique for mixing a coating liquid. Background Art

[0002] Patent Document 1 discloses a technique in which a plurality of coating materials supplied from a coating material supply pipe are mixed while passing through a static mixer provided inside a pipe.

[0003] Patent Document 1: Japanese Patent Application Publication No. 2000-153184

[0004] The static mixer disclosed in Patent Document 1 has a stirring baffle. In this technology, the substances contained in the coating liquid are easily clogged in the baffle portion. Therefore, there is a problem that cleaning takes labor and time, and the maintainability is poor. Summary of the invention

[0005] Therefore, an object of the present invention is to provide a coating liquid mixing device that is excellent in maintainability.

[0006] In order to solve the above-mentioned problems, the coating liquid mixing device comprises: a supply pipe portion, having a plurality of flow paths for respectively flowing a plurality of coating liquids, the plurality of flow paths opening at the front end side; and a mixing nozzle portion, connected to the outlet portion of the supply pipe portion so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, and having a reduced diameter portion in which the internal space becomes narrower as it proceeds toward the outlet side so that the opening area is smaller than the total opening area of ​​the plurality of flow paths.

[0007] In addition, in order to solve the above-mentioned problems, a coating liquid mixing method comprises: (a) a preparation step, preparing a supply pipe part and a mixing nozzle part, the supply pipe part having a plurality of flow paths for respectively flowing a plurality of coating liquids, the plurality of flow paths opening at the front end side, the mixing nozzle part being connected to the outlet part of the supply pipe part so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, and having a reduced diameter part in which the internal space gradually narrows as it proceeds toward the outlet so that the opening area is smaller than the total opening area of ​​the plurality of flow paths; and (b) a supply step, after the preparation step, supplying the coating liquid to the plurality of flow paths formed in the supply pipe part respectively, so that the plurality of coating liquids are mixed in the internal space of the mixing nozzle part starting from the outlet of the supply pipe part.

[0008] According to the coating liquid mixing device, the mixing nozzle portion is configured to have an internal space that narrows as it advances toward the outlet side so that the opening area is smaller than the total opening area of ​​the above-mentioned multiple flow paths. Therefore, if the coating liquid is supplied to the mixing nozzle portion from multiple flow paths respectively, the multiple coating liquids are guided in a direction of mutual mixing while increasing the flow velocity in the internal space of the mixing nozzle portion. By deflecting each coating liquid in this way, a plurality of coating liquids can be mixed. Compared with the case where a stirring baffle is provided, by deflecting the coating liquid flowing in the nozzle to perform mixing, it is possible to prevent the flow velocity of the coating liquid from becoming extremely small in an area. Thus, clogging of the coating liquid in the nozzle can be prevented. Therefore, due to the reduction in the work of eliminating clogging of the coating liquid, maintainability can be improved.

[0009] Furthermore, according to the coating liquid mixing method, the mixing nozzle unit is prepared, and the coating liquid is mixed using the mixing nozzle unit in the supplying step. This can prevent clogging of the coating liquid in the nozzle, and improve maintainability, as described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 It is an explanatory diagram showing a coating liquid mixing device according to an embodiment.

[0011] Figure 2 yes Figure 1 Partial cross-sectional view along line II-II.

[0012] Figure 3 It is an explanatory diagram showing a coating liquid mixing device according to a modified example. DETAILED DESCRIPTION

[0013] Hereinafter, a coating liquid mixing device and a coating liquid mixing method according to an embodiment will be described. Figure 1 It is an explanatory diagram showing a coating liquid mixing device according to an embodiment. Figure 2 yes Figure 1 Partial cross-sectional view along line II-II.

[0014] The coating liquid mixing device 20 is a device for mixing a plurality of coating liquids. In the present embodiment, as an example, the coating liquid mixing device 20 is provided as a part of the coating device. Specifically, the coating liquid mixing device 20 is provided in the coating device at a position close to a spray port for spraying the coating liquid. For example, the coating device is configured to include: a coating robot device capable of moving the front end to any position and posture; a spray device provided at the front end of the robot device and spraying the coating liquid; a supply device for supplying the coating liquid from a storage tank storing the coating liquid toward the spray device; and a control device. The control device controls the robot device, the spray device, and the supply device, respectively.

[0015] The control device can move the spray port of the spray device to a predetermined position and direction by giving an operation command to the robot. In addition, the control device can spray the coating liquid at a predetermined spraying time and a predetermined spraying amount by controlling the spray device and the supply device.

[0016] The coating device of the present embodiment may also include a bell-shaped cup 160 for atomizing the coating liquid. The bell-shaped cup 160 forms a retention space 163 for retaining the coating liquid, and discharges the coating liquid retained in the retention space 163 radially outward by the centrifugal force generated by the rotation. In more detail, the coating device has a mixing nozzle portion 40, which is arranged on the upstream side of the bell-shaped cup 160 and discharges the coating liquid to the retention space 163. The coating liquid discharged from the mixing nozzle portion 40 collides with the downstream wall surface 164 of the retention space 163 in the bell-shaped cup 160 in the injection direction. The bell-shaped cup 160 rotates at a high speed around the injection axis of the mixing nozzle portion 40. The coating liquid attached to the bell-shaped cup 160 in the retention space 163 rotates together with the bell-shaped cup 160, and moves radially outward due to the centrifugal force. The coating liquid is discharged from the retention space 163 to the outside of the retention space 163 from the opening S formed in the retention space 163 along the wall surface of the bell-shaped cup 160 due to the centrifugal force. The coating liquid moves in a thin film while further moving radially along the wall surface of the bell-shaped cup 160, becomes a particle at the edge of the bell-shaped cup 160, and scatters radially outward from the bell-shaped cup 160. The scattered coating liquid is further micronized due to the electrostatic effect and moves toward the coating object. In this way, the coating device of this embodiment sprays the atomized (micronized) coating liquid onto the coating object. For example, the coating device is used for exterior coating of vehicle bodies such as automobiles, two-wheeled motorcycles, or construction machinery. The coating object may also be automobile parts, electrical equipment, metal parts, etc.

[0017] A coating device according to an embodiment of the present invention mixes a plurality of coating liquids and supplies them to a retention space 163 of a bell-shaped cup 160. The coating device discharges a mixed liquid 15 into the retention space 163 of the bell-shaped cup 160, wherein the mixed liquid 15 is a mixture of a coating liquid that serves as a main agent for determining the color tone and a curing agent for curing the main agent. The mixed liquid 15 is an example of a coating liquid. The main agent is appropriately selected according to the required coating method (coating color, etc.). In addition, the curing agent can also be standardized regardless of the required coating method (coating color). For the main agent and the curing agent, known materials used as coating liquids can be used.

[0018] The coating liquid mixing device 20 includes a supply pipe section 30 and a mixing nozzle section 40. A plurality of flow paths 32 and 34 are formed in the supply pipe section 30. The curing agent 12 and the main agent 14 are respectively supplied from the base end side of the supply pipe section 30. The curing agent 12 and the main agent 14 flow in different flow paths 32 and 34, respectively, and flow out from the outlet of each flow path. The mixing nozzle section 40 is connected to the outlet portion of the supply pipe section 30. As described above, the curing agent 12 and the main agent 14 are mixed in the mixing nozzle section 40, and flow out from the outlet of the mixing nozzle section 40 toward the retention space 163 of the bell cup 160.

[0019] The supply pipe portion 30 has a plurality of flow paths formed in a tubular shape. More specifically, as a plurality of flow paths, the supply pipe portion 30 includes: a central flow path 32; and an annular flow path 34, which becomes an outer flow path. In the present embodiment, the coating liquid that becomes the main agent 14 is supplied to the annular flow path 34. In addition, the coating liquid that becomes the curing agent 12 is supplied to the central flow path 32. The curing agent 12 has a greater viscosity than the main agent 14. In addition, the curing agent 12 has a greater specific gravity than the main agent 14. In addition, the main agent 14 is supplied in a manner such that the flow rate (volume flowing per unit time) is greater than that of the curing agent 12. The main agent 14 and the curing agent 12 may also pass through the passage in opposite directions to each other.

[0020] The central flow path 32 is formed so that its central axis extends along the central axis of the supply pipe 30. An outlet opening toward the downstream side in the flow direction is formed in the central flow path 32. In the present embodiment, the central flow path 32 is formed so that the cross-sectional shape perpendicular to the central axis is circular.

[0021] The annular flow path 34 is located radially outside the central flow path 32. The annular flow path 34 is formed so that its central axis extends along the center line of the supply pipe portion 30. An outlet that is open to the downstream side of the flow direction is formed in the annular flow path 34. In this example, the annular flow path 34 is formed to surround the central flow path 32. The annular flow path 34 is formed in an annular shape that covers the central flow path 32 in the entire circumferential direction. More specifically, the annular flow path 34 is formed in a circular ring shape centered on the central axis of the central pipe. That is, the central flow path and the annular flow path are formed in a concentric circle shape.

[0022] Such a supply pipe section 30 can be formed by combining two pipes. For example, a spacer component configured to position the central pipe relative to the outer pipes may be interposed between the central pipe and the outer pipes. In this way, the state in which the annular flow path 34 is formed around the central flow path 32 can also be maintained. With respect to the flow paths of the supply pipe section, a connecting path connecting the flow paths is not formed, and the curing agent 12 and the main agent 14 flowing in the central flow path and the annular flow path flow from the inlet to the outlet in the supply pipe section 30 without mixing.

[0023] In addition to a circle, the shape of the cross section of the central flow path 32 perpendicular to the axis may be an ellipse, a polygon, etc. In addition, in addition to a circular ring, the shape of the cross section of the annular flow path 34 may be an ellipse ring, a polygonal ring. In addition, the shape and size of each flow path 32 and flow path 34 may be different on the inlet side and the outlet side of the supply pipe portion 30.

[0024] The mixing nozzle section 40 is connected to the outlet portion of the supply pipe section 30. The mixing nozzle section 40 is formed into a cylindrical shape with both ends open in the axial direction. The inlet portion of the mixing nozzle section 40 is connected to the outlet portion of the supply pipe section 30. The outlet portion of the mixing nozzle section 40 is located on the downstream side of the flow direction of the supply pipe section 30. Therefore, most of the internal space 42 of the mixing nozzle section 40 is arranged on the downstream side of the flow direction of the coating liquid than the supply pipe section 30. Specifically, the mixing nozzle section 40 is formed in a shape covering the outlet of the annular flow path 34. The outlet of the central flow path 32 and the outlet of the annular flow path 34 are open to the internal space of the mixing nozzle section 40. As a result, the curing agents 12 and the main agent 14 that have passed through the respective flow paths 32 and 34 merge in the internal space 42 of the mixing nozzle section 40. The mixing nozzle section 40 of this example is formed into a circular tube coaxial with the central axis of the supply pipe section 30. In other words, the internal space 42 of the mixing nozzle portion 40 is formed coaxially with the central flow path 32 and the annular flow path 34 .

[0025] The mixing nozzle portion 40 has a reduced diameter portion that gradually narrows as it advances toward the outlet. Specifically, in addition to the reduced diameter portion, the mixing nozzle portion 40 is also formed with: a connecting portion that is connected to the supply pipe portion 30; and an injection portion that forms an injection port. The mixing nozzle portion 40 is arranged in the axial direction to form a connecting portion, a reduced diameter portion, and an injection portion as it moves from the upstream side toward the downstream side in the flow direction. In the present example, the connecting portion is connected to the supply pipe portion 30 by fitting from the radially outer side of the supply pipe portion 30. The connecting portion is connected to the reduced diameter portion on the downstream side in the flow direction. In addition, the reduced diameter portion is connected to the injection portion on the downstream side in the flow direction. In the present example, the injection portion is formed into a circular tube having the same diameter in the entire axial direction.

[0026] like Figure 2As shown, the internal space 42 of the mixing nozzle portion 40 is formed so that the opening area S4 on the outlet side forming the injection port is smaller than the total opening area S1 of each flow path 32, 34 (S4<S1). Specifically, the internal space 42 is formed into a shape in which the cross-sectional area gradually narrows as it advances toward the injection port that becomes the outlet by the reduced diameter portion. In the present embodiment, the total opening area S1 of each flow path 32, 34 is the sum of the opening area S2 on the outlet side of the central flow path 32 and the opening area S3 on the outlet side of the annular flow path 34. Here, the internal space 42 includes a base end side space 43, an intermediate space 44, and a front end side space 45. The base end side space 43 is formed into a cylindrical shape having an outer diameter greater than the outer diameter of the annular flow path 34. Here, the outer diameter of the base end side space 43 is set to the same size as the outer diameter of the supply pipe portion 30, and the base end side space 43 extends further downstream in the flow direction from the outlet side end of the supply pipe portion 30. The front end side space 45 is formed as a cylindrical space portion having an outer diameter smaller than that of the base end side space 43. The area S4 of the front end side opening of the front end side space 45 is smaller than the above-mentioned total area S1. In the present embodiment, the area S4 of the front end side space 45 is set smaller than the opening area S2 of the central flow path 32. In addition, the cross-sectional area (cross-sectional area in the direction along the axis) of the central flow path 32 may also be larger than the cross-sectional area of ​​the annular flow path 34 on the outer peripheral side.

[0027] The intermediate space 44 is formed in a shape that gradually narrows from the base end side space 43 toward the front end side space 45. Here, the intermediate space 44 is formed in a shape in which the outer diameter continuously decreases from the base end side space 43 toward the front end side space 45. In other words, the intermediate space 44 is formed in a truncated cone-shaped space with the top of the cone cut off.

[0028] Such a mixing nozzle part 40 can also be formed by ductilely deforming a metal pipe or performing cutting. In this example, the outer shape of the mixing nozzle part 40 is also formed into a shape corresponding to the above-mentioned internal space 42. The above-mentioned internal space 42 can be formed in the mixing nozzle part 40, and the outer shape of the mixing nozzle part 40 is not particularly limited.

[0029] In the present embodiment, the supply pipe part 30 and the mixing nozzle part 40 are formed independently. The outer diameter of the front end of the supply pipe part 30 and the inner diameter of the base end of the mixing nozzle part 40 are set to a size that can fit the base end of the mixing nozzle part 40 outside the front end of the supply pipe part 30. Therefore, the base end of the mixing nozzle part 40 can be fitted outside the front end of the supply pipe part 30, thereby having an installation structure in which the mixing nozzle part 40 can be installed on the supply pipe part 30 in a detachable manner. The structure in which the mixing nozzle part 40 can be installed on the supply pipe part 30 in a detachable manner can also be a structure in which one of the front end of the supply pipe part and the base end of the mixing nozzle part is pressed relative to the other. In addition, for example, an anti-slip structure for maintaining the connection state can also be formed at the connection part between the supply pipe part and the mixing nozzle part. For example, it is configured to be detachable by a fastening component such as a bolt component or a clamping component. The installation structure can also be a structure in which a thread groove that is screwed together is formed at the front end of the supply pipe part and the base end of the mixing nozzle part, and the two are screwed together. The mounting structure may be a structure in which a screw screwed into the mixing nozzle portion is pressed against the outer periphery of the supply pipe portion 30, or a structure in which a hook structure provided on one of the supply pipe portion 30 and the mixing nozzle portion 40 is hooked on the other.

[0030] The structure for supplying the curing agent 12 and the main agent 14 to each flow path 32, 34 is described. The curing agent supply source 60 and the base end of the supply pipe portion 30 are connected via a curing agent supply body 61. The pipeline in the curing agent supply body 61 is connected to the central flow path 32. The curing agent supply source 60 is a tank for storing the coating liquid 12, that is, the curing agent 12. A curing agent pump 62 is provided in the middle of the curing agent supply body 61. The curing agent 12 stored in the curing agent supply source 60 is supplied to the central flow path 32 by driving the curing agent pump 62. The flow rate (pressure) of the curing agent 12 flowing in the central flow path 32 is adjusted by controlling the driving of the curing agent pump 62.

[0031] The main agent supply source 66 and the base end of the supply pipe portion 30 are connected via a main agent supply body 67. The pipeline in the main agent supply body 67 is connected to the annular flow path 34. The main agent supply source 66 is a tank for storing the coating liquid 14, that is, the main agent 14. A main agent pump 68 is provided in the middle of the main agent supply body 67. The main agent 14 stored in the main agent supply source 66 is supplied toward the annular flow path 34 by driving the main agent pump 68. The flow rate (pressure) of the main agent 14 flowing in the annular flow path 34 is adjusted by controlling the action of the main agent pump 68. The above-mentioned pumps 62 and 68 are connected to a control unit 16. The control unit 16 is composed of a computer having a CPU (Central Processing Unit), a main storage device, an auxiliary storage device, etc. The control unit 16 controls the action of each pump 62 and 68 by acting according to a program stored in the auxiliary storage device, etc. Thus, the supply and stop of the curing agent 12 and the main agent 14 to each flow path 32, 34, the flow rate in the flow paths 32, 34, etc. can be adjusted. The supply and stop of the curing agent 12 and the main agent 14 to each flow path 32, 34, the flow rate in the flow paths 32, 34, etc. can also be performed by driving control of electromagnetic regulating valves or the like provided in the supply bodies 61, 67.

[0032] The annular flow path for supplying the main agent can also be configured to switch between multiple types of main agent supplies. In this case, a tank and a main agent supply body are provided for each different type of main agent, and a switching device for switching the supply path is provided. The control unit can switch the main agent supplied to the supply pipe by controlling the switching device. Thus, the control device can supply different main agents according to the coating object.

[0033] The coating liquid mixing method is described. The coating liquid mixing method comprises: (a) a preparation step of preparing the supply pipe section 30 and the mixing nozzle section 40; and (b) a supply step of supplying the curing agent 12 and the main agent 14 to the plurality of flow paths 32 and 34 formed in the supply pipe section 30 respectively after the preparation step, so that the plurality of curing agents 12 and the main agent 14 are mixed in the internal space 42 of the mixing nozzle section 40 from the outlet of the supply pipe section 30.

[0034] The internal space 42 of the mixing nozzle part 40 is a space for mixing the curing agent 12 and the main agent 14, so it is an example of a mixing space. The internal space 42 has a reduced diameter portion that becomes narrower as it moves toward the outlet side. Therefore, the curing agent 12 and the main agent 14 are guided in the direction of mutual mixing while increasing the flow rate in the internal space 42 of the mixing nozzle part 40. The curing agent 12 and the main agent 14 can be mixed by deflecting each curing agent 12 and the main agent 14 in this way. Compared with the case where a stirring baffle is set on the supply body, by performing so-called shear mixing in this way, it is possible to prevent the area where the flow rate of the coating liquid becomes extremely small. Thus, clogging of the coating liquid in the nozzle can be prevented. Therefore, due to the reduction of the work of eliminating the clogging of the coating liquid, the maintainability can be improved. In this embodiment, since the clogging of the coating liquid can be prevented in this way, in addition to the reduction of the working process, the amount of cleaning agent used to eliminate the clogging of the coating liquid can also be reduced. Thus, the waste liquid treatment of the cleaning agent can be reduced, and the cost of waste liquid treatment and the load on the environment can be reduced. In addition, shear mixing here means mixing while mainly applying shear force to each coating liquid.

[0035] In the present embodiment, the flow rate (volume flowing per unit time) of the main agent 14 flowing in the annular flow path 34 is set to be greater than the flow rate of the curing agent 12 flowing in the central flow path 32. In addition, the flow rate of the main agent 14 flowing in the annular flow path 34 may be set to be greater than the flow rate of the curing agent 12 flowing in the central flow path 32. The flow rate here refers to the flow rate at the outlet opening in the central flow path 32 and the annular flow path 34. Such a flow rate or flow rate setting may also be achieved by controlling the driving of the above-mentioned pumps 62, 68, etc., in view of the flow path areas of the central flow path 32 and the annular flow path 34.

[0036] The main agent 14 is supplied from the annular flow path 34 toward the radially outer area in the internal space 42. As described above, in the internal space 42, the inner circumferential wall surrounding the main agent 14 supplied by the annular flow path 34 is narrowed. As a result, the main agent 14 is deflected toward the radially inner area due to the inner circumferential wall of the internal space 42, and the flow rate is further increased. As a result, the main agent 14 easily goes toward the curing agent 12 flowing radially inward, making it easy for the main agent 14 and the curing agent 12 to mix. In other words, by increasing the flow rate (flow rate) of the main agent 14, it is easy to form a flow of the main agent 14 toward the radial inner side in the internal space 42, which can further promote the so-called shear mixing. In addition, the flow rate (or flow rate) of the curing agent 12 flowing in the central flow path 32 can be the same as the flow rate (or flow rate) of the main agent 14 flowing in the annular flow path 34, or it can be set to be larger.

[0037] In addition, in the present embodiment, the viscosity of the main agent 14 flowing in the annular flow path 34 is set to be lower than the viscosity of the curing agent 12 flowing in the central flow path 32. This setting can also be achieved by making the viscosity of the curing agent 12 stored in the curing agent supply source 60 higher than the viscosity of the main agent 14 stored in the main agent supply source 66.

[0038] By reducing the viscosity of the main agent 14 flowing in the annular flow path 34 in this way, the main agent 14 flowing in the radially outer side can be easily deflected in the internal space 42. As a result, the main agent 14 flowing in the radially outer side is easy to go to the radially inner side, and the flow of the main agent 14 from the radially outer side to the radially inner side is easy to form in the internal space 42, which can further promote the so-called shear mixing. In addition, the viscosity of the curing agent 12 flowing in the central flow path 32 can also be the same as the viscosity of the main agent 14 flowing in the annular flow path 34, or it can be set to be larger.

[0039] According to the coating liquid mixing device 20 and the coating liquid mixing method configured in this way, a plurality of coating liquids 12 and 14 can be mixed as described above. In the present embodiment, the mixed liquid 15 discharged from the mixing nozzle unit 40 reaches the retention space 163 in the bell cup 160 and is further stirred in the bell cup 160. Thus, the mixing before reaching the coating object can be further improved. In other words, since the mixing can be performed in both the bell cup 160 and the mixing nozzle unit 40, the mixing before reaching the coating object can be improved compared to the case where the mixing is performed only in the mixing nozzle unit 40.

[0040] In addition, the internal space of the mixing nozzle portion 40 can also be formed as an intermediate space 44 that is continuously and slowly narrowed toward the front end side space 45. In this case, the corners to which the curing agent 12 and the main agent 14 are easily attached can be suppressed. In addition, even if the curing agent 12 and the main agent 14 are attached to the inner circumferential wall of the mixing nozzle portion 40, the attached matter can be easily cleaned with a cleaning fluid because the inner circumferential surface is prevented from being uneven. Therefore, the cleaning of the mixing nozzle portion 40 becomes easy, and the maintainability is excellent. In addition, in the present embodiment, the internal space is in the shape of a truncated cone, but as a cross-sectional shape passing through the axis, it can also be formed in other shapes. For example, the inner circumferential surface can also be a shape that extends in a curved shape, such as a parabola, and gradually narrows in diameter as it moves toward the outlet side.

[0041] In addition, the annular flow path 34 may be formed in an annular shape surrounding the central flow path 32 in the circumferential direction. In this case, the main agent 14 supplied from the annular flow path 34 to the mixing nozzle portion 40 can be guided from the area covering the entire circumference of the central axis toward the central axis of the mixing nozzle portion 40. Thus, the deviation of the mixing state in the circumferential direction can be suppressed. Thus, the curing agent 12 and the main agent 14 can be further appropriately mixed.

[0042] In addition, the mixing nozzle part 40 can also be formed to be able to be loaded and unloaded relative to the supply pipe part 30. In this case, the mixing nozzle part 40 can be removed from the supply pipe part 30 to clean the mixing nozzle part 40. The mixing nozzle part 40 mixes the main agent 14 and the curing agent 12, and is thus a part that is easy to produce adhesion caused by curing compared to the part on the upstream side. By removing this part, the adhesion part can be cleaned intensively compared to the case where the supply pipe part 30 is included in the cleaning. From this point of view, the maintenance of the coating liquid mixing device 20 is also easy. And in the present embodiment, the mixing nozzle part 40 is connected to the downstream end part (front end part) that becomes the downstream side outlet of the supply pipe part 30. Therefore, it is easy to operate and handle from the downstream side that becomes the bell cup 160 compared to the case where it is arranged on the upstream side of the supply pipe part 30. Therefore, it is easy to load and unload the mixing nozzle part 40, and the disassembly operation time for cleaning the mixing nozzle part 40 can be shortened.

[0043] In addition, the mixing nozzle portion 40 may be configured such that the front end side opening area S4 of the internal space 42 thereof is smaller than the total opening area S1 of the plurality of flow paths 32, 34 (S4 < S1). In this case, the flow rate of the curing agent 12 and the main agent 14 in the state of being discharged from the mixing nozzle portion 40 can be increased compared to the state in which the curing agent 12 and the main agent 14 flow in the supply pipe portion. By thus shrinking the front end side opening area, mixing in the mixing space can be promoted, and the mixing of the curing agents 12 and the main agent 14 can be improved. In addition, by forming the opening area of ​​the region on the upstream side of the mixing nozzle portion 40 relative to the outlet smaller than the total opening area S1 of the plurality of flow paths 32, 34, the flow rate of the curing agents 12 and the main agent 14 can be increased before discharge, and the mixing can be further improved.

[0044] In addition, the opening area S2 of the central flow path 32 may be larger than the area S4 of the outlet of the mixing nozzle 40. In this case, by strengthening the contraction state, the mixing in the mixing space can be further promoted. In addition, the flow rate of each curing agent 12 and the main agent 14 is further increased in the mixing nozzle 40. Therefore, the mixing of the curing agent 12 and the main agent 14 can be further promoted.

[0045] The mixing device 20 may also be provided with an outer peripheral flow path 136 on the outer peripheral side of the flow paths 32 and 34. For example, the outer tube portion 132 is provided around the supply tube portion 30. An annular outer peripheral flow path 136 is formed between the supply tube portion 30 and the outer tube portion 132. The outer peripheral flow path 136 does not necessarily need to be annular, and may be formed in a hole shape.

[0046] The opening of the outer peripheral flow path 136 opens on the outer peripheral side of the mixing nozzle part 40. In addition, the opening of the outer tube part 132 may also open closer to the front side than the opening of the mixing nozzle part 40. More specifically, the outer tube part 132 is provided to be spaced apart from the outer peripheral surface of the supply tube part 30. The mixing nozzle part 40 covers the front end portion of the supply tube part 30. A gap is also formed between the outer peripheral surface of the base end side of the mixing nozzle part 40 and the outer tube part 132. The opening between the outer peripheral surface of the supply tube part 30 and the outer tube part 132 opens on the outer peripheral side of the mixing nozzle part 40. In addition, the front end portion of the outer tube part 132 is located closer to the front than the opening of the mixing nozzle part 40. Therefore, the opening of the outer peripheral flow path 136 is located closer to the front than the opening of the mixing nozzle part 40. Here, the outer peripheral flow path 136 opens closer to the front than the bell cup 160.

[0047] The cleaning liquid from the cleaning liquid supply source 71 is supplied to the outer peripheral flow path 136 by the pump 73 through the cleaning liquid supply body 72. The cleaning liquid can be selected according to the types of the curing agent 12 and the main agent 14, and can be selected so as to easily dissolve these liquids.

[0048] If the outer peripheral flow path 136 is provided in this way, the outer peripheral side and the front end side of the mixing nozzle part 40 can be cleaned by flowing the cleaning liquid 112 into the outer peripheral flow path 136. At this time, the outer peripheral flow path 136 passes through the outer peripheral side of the mixing nozzle part 40 to reach the front end side thereof, so it is difficult to reach the openings of the flow paths 32 and 34. Therefore, the cleaning liquid 112 is not easily mixed into the curing agent 12 and the main agent 14 supplied from the flow paths 32 and 34, and a stable mixed liquid 15 can be manufactured.

[0049] {Variation Example}

[0050] In this embodiment, an example is shown in which the mixing device 20 is used in a coating device using the bell cup 160, but the present invention is not limited thereto. That is, it can also be applied to a device that atomizes the mixed coating liquid using a mechanism other than the bell cup 160. For example, the same effect can be obtained by using the mixing device of the present invention in the discharge part of a spray gun that contains the coating liquid in compressed air and discharges it.

[0051] In addition, in the present embodiment, an example is described in which the opening area S2 of the central flow path 32 is formed to be larger than the area S4 of the outlet of the mixing nozzle portion 40, but the opening area S2 of the central flow path 32 and the area S4 of the outlet of the mixing nozzle portion 40 may be the same, or the opening area S2 of the central flow path 32 may be formed to be smaller than the area S4 of the outlet of the mixing nozzle portion 40.

[0052] In addition, in the present embodiment, the mixing nozzle part 40 can be attached and detached relative to the supply pipe part 30, but it is not necessarily detachable. The mixing nozzle part and the supply pipe part are also formed in one piece. In addition, in the case of forming in one piece, the outer diameter of the outlet side of the annular flow path and the outer diameter of the inlet side of the mixing nozzle part are easily formed into the same shape. As a result, the coating liquid can flow smoothly from the annular flow path to the mixing nozzle part.

[0053] Furthermore, in each of the above-mentioned embodiments, the plurality of flow paths do not necessarily have to include the central flow path 32 and the annular flow path 34. For example, the plurality of flow paths may also be a plurality of hole-shaped flow paths formed in parallel. In addition, for example, it may also include: the central flow path 32; and an outer flow path, which is located radially outward relative to the central flow path. For example, a plurality of outer flow paths may also be provided in the circumferential direction of the central flow path. For example, main agents of different components may also be supplied to the plurality of outer flow paths, respectively. In addition, in the present embodiment, an annular path for the flow of the cleaning liquid is formed around the radial outer side of the annular flow path, but the case where such an annular path is not formed is also included in the present invention.

[0054] In addition, in the present embodiment, the reduced diameter portion is a structure in which the opening area gradually narrows toward the outlet side, but it can also be formed into a stepped step shape. In addition, the case where the central flow path and the annular flow path are formed into non-concentric circles is also included in the present invention. In addition, it is preferred that the mixing nozzle portion is installed on the downstream end side of the supply pipe portion, but regarding the installation position, the case where it is installed at other positions is also included in the present invention. For example, the supply pipe and the mixing nozzle portion of the coating device rotate together with the bell cup, but it can also be set in a portion that does not rotate relative to the bell cup, such as the case where it is set at a position separated from the bell cup. In addition, the flow velocity, flow rate, viscosity, contained substances and materials of the coating liquid flowing in each flow path are not limited to the present embodiment, and the case of using other settings is also included in the present invention.

[0055] In addition, the structure that enables the supply pipe part 30 and the mixing nozzle part 40 to be attached and detached is not limited to the above example. For example, the flange part around the supply pipe part 30 and the base end part of the mixing nozzle part 40 may be screwed and fixed in a state where the front end part of the supply pipe part 30 and the base end part of the mixing nozzle part 40 are arranged in an opposed state. In addition, the mixing nozzle part 40 does not necessarily have to be formed independently of the supply pipe part 30. The mixing nozzle part 40 and the supply pipe part 30 may also be formed integrally.

[0056] In the mixing nozzle portion, the space that gradually narrows toward the front end side may exist in the middle portion of the extension direction of the mixing nozzle portion 40 as in the above-mentioned embodiment, may exist in the area reaching the front end side of the mixing nozzle portion, may exist on the base end side, or may exist in the entire extension direction of the mixing nozzle portion. This means that the space that gradually narrows in the mixing nozzle portion only needs to exist in at least a portion of the extension direction of the mixing nozzle portion. The intermediate space 44 does not necessarily have to be formed in a shape that gradually narrows toward the front end side. The mixing nozzle portion may also be formed in a shape that narrows toward the front end side via a step as described above.

[0057] When three or more coating liquids are mixed, three or more flow paths may be formed in the supply pipe portion. In this case, as described above, a plurality of annular flow paths may be formed concentrically around the central flow path.

[0058] In the embodiment, the mixing nozzle unit 40 may be covered on the outer peripheral side of the outer peripheral flow path 136 so that the cleaning liquid passes through the mixing nozzle unit 40. In this case, the inside of the mixing nozzle unit 40 can be cleaned.

[0059] Figure 3 1 is an explanatory diagram showing a coating liquid mixing device 20B involved in a modified example. As shown in the figure, a tube portion 134 is added to the inner side of the outer tube portion 132. A mixing nozzle portion 140 corresponding to the mixing nozzle portion 40 is installed at the front end portion of the tube portion 134. In the modified example, the mixing nozzle portion 140 is externally embedded at the front end portion of the tube portion 134. A gap is provided between the inner peripheral surface of the outer tube portion 132 and the outer peripheral surface of the tube portion 134, and a gap is also provided between the inner peripheral surface of the outer tube portion 132 and the outer peripheral portion of the base end side of the mixing nozzle portion 140. In a state where the tube portion 134, the mixing nozzle portion 140 and their inner parts are stopped from rotating, the outer tube portion 132 and the bell cup 160 are rotationally driven by a rotation drive portion such as a motor.

[0060] The tube portion 134 covers the outer peripheral side of the supply tube portion 30B corresponding to the supply tube portion 30 with a gap therebetween. The cleaning liquid is supplied to the mixing nozzle portion 140 through the gap of the annular flow path 136B between the supply tube portion 30B and the tube portion 134, and is discharged to the outside from the mixing nozzle portion 140. Since the cleaning liquid passes through the mixing nozzle portion 140, the cleaning liquid can clean the inside of the mixing nozzle portion 140.

[0061] In this case, a recess 35a may also be formed in the outermost annular peripheral portion of the front end side of the supply pipe portion 30B corresponding to the supply pipe portion 30. More specifically, a recess 35a is formed in the annular peripheral portion of the outer peripheral side of the supply pipe portion 30B (here, the open end edge portion of the tube that divides the outer periphery of the annular flow path 34). The recess 35a is formed, for example, in a notch shape that is recessed from the front end portion of the supply pipe portion 30B toward the base end portion. The recess 35a may be a square-shaped depression, a slit-shaped depression that is longer in the axial direction of the supply pipe portion 30B, or a semicircular or triangular depression. The recess 35a may be formed in one or more annular peripheral portion of the front end side of the supply pipe portion 30B. The depth of the recess 35a (the length in the axial direction of the supply pipe portion 30B) and the width of the recess 35a (the length in the circumferential direction of the supply pipe portion 30B) are arbitrary, but for example, can also be about 1 / 4 to 2 / 3 of the diameter of the central flow path 32.

[0062] The base end of the mixing nozzle portion 140 is formed in a shape that expands radially outward via the step portion 141S. When the base end of the mixing nozzle portion 140 is externally fitted to the front end of the tube portion 134, the inward facing surface 141Sa of the step portion 141S covers the open end of the tube portion 134. The inward facing surface 141Sa may be in contact with the open end of the tube portion 134. In addition, the inward facing surface 141Sa may be separated from the open end of the tube portion 134.

[0063] The cleaning liquid hits the inward-facing surface 141Sa and flows on the front end side of the annular flow path 34 through the recess 35a. At this time, a flow toward the radial inner side of the annular flow path 34 is formed. If the inward-facing surface 141Sa is connected to the open end of the tube portion 134, all the cleaning liquid passes through the recess 35a, and the cleaning liquid is more reliably deflected inward. As a result, it is possible to prevent the cleaning liquid from flowing along the inner circumferential surface of the mixing nozzle portion 140 in the mixing nozzle portion 140, forming a radially inner flow, and forming a flow that swirls radially inward. As a result, it is easy for the cleaning liquid to be immersed from the recess 35a toward the upstream side of the annular flow path 34.

[0064] In addition, the total cross-sectional area in the radial direction of the flow path through which the cleaning liquid flows from the flow path 136B to the inside (the total cross-sectional area of ​​the concave portion 35a along the radial direction of the tube portion 30B when the inwardly facing surface 141Sa is in contact with the open end of the tube portion 134) is formed to be smaller than the cross-sectional area of ​​the flow path through which the cleaning liquid passes (the gap between the tube portion 134 and the supply tube portion 30B, that is, the cross-sectional area in the direction perpendicular to the axis of the tube portion 134). As a result, the flow rate of the cleaning liquid passing through the concave portion 35a can be increased compared to the flow rate of the cleaning liquid flowing on the upstream side of the concave portion 35a.

[0065] In this way, by providing the recessed portion 35 a as an example of a guide portion that guides the cleaning liquid further radially inward than the inclination of the mixing nozzle portion 140 , the cleaning effect can be improved.

[0066] In this embodiment, the base end of the mixing nozzle 140 completely covers the open end of the supply pipe 30B that defines the inner portion of the cleaning liquid passage. The base end of the mixing nozzle 140 may cover a portion of the open end of the supply pipe 30B or may not cover it.

[0067] The shape of the recessed portion 35a is not particularly limited as long as it is a shape that penetrates the supply pipe portion 30B in the radial direction. In addition, the guide portion that guides the cleaning liquid to the inner side of the mixing nozzle portion 140 does not necessarily have to be a recessed portion that penetrates the supply pipe portion 30B in the radial direction. For example, the inward-facing surface 141Sa itself can also be a guide member that guides the cleaning liquid to the inner side of the mixing nozzle portion 140. In this case, the recessed portion 35a can also be omitted. In addition, a guide flow path that guides the cleaning liquid to the inner side of the mixing nozzle portion 140 can also be formed by a combination of concave and convex shapes between the outer peripheral side of the front end of the supply pipe portion and the inward-facing surface 141Sa.

[0068] Furthermore, the present invention also includes the case where only two-liquid mixed coating is performed without causing the cleaning liquid to flow.

[0069] In addition, the respective configurations described in the above-mentioned embodiment and the respective modifications can be appropriately combined as long as they do not contradict each other.

[0070] As described above, the present invention has been described in detail, but the above description is illustrative in all aspects and the present invention is not limited thereto. It is understood that numerous modifications of the illustrative examples can be conceived without departing from the scope of the present invention.

[0071] As described above, this specification includes the following aspects.

[0072] The first form is a coating liquid mixing device, which comprises: a supply pipe portion, having a plurality of flow paths for respectively flowing a plurality of coating liquids, the plurality of flow paths opening at the front end side; and a mixing nozzle portion, connected to the outlet portion of the supply pipe portion so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, the mixing nozzle portion having a reduced diameter portion in which the internal space becomes narrower as it proceeds toward the outlet side so that the opening area is smaller than the total opening area of ​​the plurality of flow paths.

[0073] For the present mixing device, the mixing nozzle portion is configured to have an internal space having a shape that narrows as it advances toward the outlet side so that the opening area is smaller than the total opening area of ​​the above-mentioned multiple flow paths. Therefore, if the coating liquid is supplied to the mixing nozzle portion from multiple flow paths respectively, the multiple coating liquids are guided in a direction of mutual mixing while increasing the flow velocity in the internal space of the mixing nozzle portion. By deflecting each coating liquid in this way, a plurality of coating liquids can be mixed. Compared with the case where a stirring baffle is provided, by deflecting the coating liquid flowing in the nozzle to perform mixing, it is possible to prevent the flow velocity of the coating liquid from becoming extremely small in an area. Thus, clogging of the coating liquid in the nozzle can be prevented. Therefore, due to the reduction in the work of eliminating clogging of the coating liquid, maintainability can be improved.

[0074] The second form is a coating liquid mixing device involved in the first form, wherein the above-mentioned diameter reduction portion is formed into a shape in which the opening area gradually narrows as it moves toward the outlet. In this case, the corner portion to which the coating liquid is easily attached can be suppressed. In addition, even if the coating liquid adheres to the inner peripheral wall of the mixing nozzle part, the attached matter can be easily cleaned with a cleaning liquid because the inner peripheral surface is prevented from being uneven. Therefore, the cleaning of the mixing nozzle part becomes easy, and the maintainability is excellent.

[0075] The third form is a coating liquid mixing device involved in the first or second form, wherein the plurality of flow paths include: a central flow path; and an annular flow path surrounding the central flow path in the circumferential direction. Thus, the coating liquid supplied from the annular flow path to the mixing nozzle portion can be guided from the area throughout the entire circumference of the central axis toward the central axis of the mixing nozzle portion. Thus, the deviation in the mixing condition in the circumferential direction can be suppressed. Thus, the coating liquid can be further properly mixed.

[0076] The fourth aspect is a coating liquid mixing device according to any one of the first to third aspects, wherein the mixing nozzle is configured to be removable relative to the supply pipe. Thus, the mixing nozzle can be removed from the supply pipe to clean the mixing nozzle. From this point of view, the maintenance of the coating liquid mixing device is also facilitated.

[0077] The fifth form is a coating liquid mixing device according to any one of the first to fourth forms, wherein the mixing nozzle is mounted on the downstream end of the supply pipe. Thus, compared with a case where the mixing nozzle is disposed on the upstream side of the supply pipe, it is easier to operate from the downstream side. Thus, the mixing nozzle is easier to load and unload, and the time required for disassembly of the mixing nozzle for cleaning can be shortened.

[0078] The sixth form is a coating liquid mixing device involved in any one of the first to fifth forms, wherein the plurality of flow paths include: a central flow path, which is arranged at the center of the supply pipe portion; and an outer flow path, which is located radially outside the central flow path, and the opening area on the outlet side of the mixing nozzle portion is smaller than the opening area on the outlet side of the central flow path. Thus, by strengthening the contraction state generated by the mixing nozzle portion, mixing in the mixing space can be further promoted. In addition, the flow velocity of each coating liquid is further increased in the mixing nozzle portion. Therefore, mixing of the coating liquid can be further promoted.

[0079] The seventh aspect is a coating liquid mixing device according to any one of the first to sixth aspects, wherein a rotating component is provided, the rotating component forms a retention space for the coating liquid ejected from the mixing nozzle portion to retain, and the coating liquid retained in the retention space is discharged radially outward by the centrifugal force generated by the rotation. In this case, the liquid discharged from the mixing nozzle portion reaches the retention space in the bell-shaped cup and is further stirred in the bell-shaped cup. Thus, the mixing before reaching the coating object can be further improved.

[0080] The eighth aspect is a coating liquid mixing device according to any one of the first to seventh aspects, wherein the coating liquid mixing device further comprises a pipe portion, the pipe portion covers the outer peripheral side of the supply pipe portion, is connected to the mixing nozzle portion, and a cleaning liquid flow path is formed between the supply pipe portion and the pipe portion, and the cleaning liquid flow path allows cleaning liquid to pass between the supply pipe portion and the pipe portion and be supplied to the internal space of the mixing nozzle portion. Thus, the inside of the mixing nozzle portion can be cleaned by the cleaning liquid.

[0081] The coating liquid mixing method involved in the ninth form includes: (a) a preparation step, preparing a supply pipe part and a mixing nozzle part, the supply pipe part having a plurality of flow paths for respectively flowing a plurality of coating liquids, the plurality of flow paths opening at the front end side, the mixing nozzle part being connected to the outlet part of the supply pipe part so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, and having a reduced diameter part in which the internal space gradually narrows as it proceeds toward the outlet so that the opening area is smaller than the total opening area of ​​the plurality of flow paths; and (b) a supply step, after the preparation step, supplying the coating liquid to the plurality of flow paths formed in the supply pipe part respectively, so that the plurality of coating liquids are mixed in the internal space of the mixing nozzle part starting from the outlet of the supply pipe part.

[0082] According to the coating liquid mixing method, the mixing nozzle unit is prepared, and the coating liquid is mixed using the mixing nozzle unit in the supply step. This can prevent the coating liquid in the nozzle from being clogged, thereby improving maintainability.

[0083] The tenth form is a coating liquid mixing method involved in the ninth form, wherein, in the above-mentioned preparation step (a), a supply pipe part is prepared, and the above-mentioned multiple flow paths of the supply pipe part include: a central flow path; and an annular flow path, which surrounds the above-mentioned central flow path in the circumferential direction, and in the above-mentioned supply step (b), different coating liquids are respectively supplied to the above-mentioned central flow path and the above-mentioned annular flow path, and the flow rate of the coating liquid flowing in the above-mentioned annular flow path is set to be greater than the flow rate of the coating liquid flowing in the above-mentioned central flow path. In the internal space of the mixing nozzle part, the inner circumferential wall surrounding the coating liquid supplied by the annular flow path is narrowed. As a result, it is deflected to the radial inner area through the inner circumferential wall of the internal space, and the flow rate is further increased. As a result, the coating liquid supplied by the annular flow path easily goes toward the coating liquid supplied by the central flow path, making it easy to mix multiple coating liquids.

[0084] The eleventh form is a coating liquid mixing method according to the ninth or tenth form, wherein in the preparation step (a), a supply pipe is prepared, wherein the plurality of flow paths of the supply pipe include: a central flow path; and an annular flow path surrounding the central flow path in the circumferential direction, and in the supply step (b), the viscosity of the coating liquid supplied to the annular flow path is set to be less than the viscosity of the coating liquid supplied to the central flow path. Thus, the coating liquid flowing radially outward can be easily deflected in the internal space of the mixing nozzle. Thus, the coating liquid flowing radially outward can easily go radially inward, and a flow of the coating liquid from the radially outside to the radially inside can be easily formed in the internal space, which can further promote the so-called shear mixing.

[0085] The twelfth form is a coating liquid mixing method involved in any one of the ninth to eleventh forms, wherein in the above-mentioned preparation step (a), a supply pipe part is prepared, and the above-mentioned multiple flow paths of the supply pipe part include: a central flow path; and an annular flow path, which surrounds the above-mentioned central flow path in the circumferential direction, and in the above-mentioned supply step (b), the coating liquid that becomes the main agent is supplied to the above-mentioned annular flow path, and the curing agent for curing the above-mentioned main agent is supplied to the above-mentioned central flow path. The coating liquid that becomes the main agent is deflected to the radially inner area through the internal space of the mixing nozzle part, and the flow rate is further increased. As a result, the main agent easily goes toward the curing agent flowing radially inward, so that the main agent and the curing agent are easily mixed.

[0086] Description of Reference Numerals

[0087] 12…curing agent (coating liquid); 14…main agent (coating liquid); 20, 20B…coating liquid mixing device; 30…supply pipe; 32…central flow path; 34…annular flow path; 40…mixing nozzle; 42…internal space; 134…pipe; 160…bell cup; 163…retention space; S1…total opening area; S2…opening area of ​​the central flow path; S3…opening area of ​​the annular flow path; S4…opening area of ​​the mixing nozzle.

Claims

1. A coating liquid mixing device, characterized in that: have: a supply pipe portion having a plurality of flow paths through which a plurality of coating liquids flow respectively, the plurality of flow paths opening at a front end side; and a mixing nozzle portion connected to the outlet portion of the supply pipe portion so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, and having a reduced diameter portion in which the internal space becomes narrower as it advances toward the outlet side so that the opening area is smaller than the total opening area of ​​the plurality of flow paths, so that the plurality of coating liquids are mixed in the internal space of the mixing nozzle portion from the outlet of the supply pipe portion, One of the plurality of flow paths is a flow path for the main agent to flow, Another flow path among the plurality of flow paths is a flow path for a curing agent to flow, The main agent and the curing agent are mixed in the internal space of the mixing nozzle. The internal space includes a base end side space, a middle space and a front end side space. The outer diameter of the base end side space is set to be the same as the outer diameter of the supply tube part. The base end side space extends from the outlet side end of the supply pipe portion toward the downstream in the flow direction of the coating liquid. The intermediate space is formed in a shape that gradually narrows from the base end side space toward the front end side space.

2. The coating liquid mixing device according to claim 1, characterized in that: The reduced diameter portion is formed in a shape in which the opening area gradually narrows as it goes toward the outlet.

3. The coating liquid mixing device according to claim 1, characterized in that: The plurality of flow paths include: a central flow path; and an annular flow path surrounding the central flow path in a circumferential direction, The outlet of the mixing nozzle portion is arranged coaxially with the central axis of the central flow path.

4. The coating liquid mixing device according to claim 1, characterized in that: The mixing nozzle portion is formed to be attachable to and detachable from the supply pipe portion.

5. The coating liquid mixing device according to claim 1, characterized in that: The mixing nozzle portion is mounted on the downstream end portion of the supply pipe portion, The mixing nozzle portion is fitted into the supply pipe portion from the radially outer side of the supply pipe portion.

6. The coating liquid mixing device according to claim 1, characterized in that: The plurality of flow paths include: a central flow path disposed at the center of the supply pipe portion; and an outer flow path located radially outward of the central flow path. An opening area on the outlet side of the mixing nozzle portion is smaller than an opening area on the outlet side of the central flow path.

7. The coating liquid mixing device according to claim 1, characterized in that: A rotating member is provided that forms a retention space in which the coating liquid ejected from the mixing nozzle portion retains, and discharges the coating liquid retained in the retention space radially outward by centrifugal force generated by rotation.

8. The coating liquid mixing device according to claim 1, characterized in that: The mixing nozzle is further provided with a pipe portion, the pipe portion covers the outer peripheral side of the supply pipe portion and is connected to the mixing nozzle portion. A flow path for cleaning liquid is formed between the supply pipe section and the pipe section, and the cleaning liquid is supplied to the internal space of the mixing nozzle section by passing through between the supply pipe section and the pipe section.

9. A coating liquid mixing method, characterized in that: have: (a) a preparation step of preparing a supply pipe section and a mixing nozzle section, wherein the supply pipe section has a plurality of flow paths for respectively flowing a plurality of coating liquids, the plurality of flow paths opening at the front end side, the mixing nozzle section being connected to an outlet portion of the supply pipe section so as to supply the coating liquid flowing in the plurality of flow paths to the internal space, and having a reduced diameter portion in which the internal space gradually narrows as it advances toward the outlet so that an opening area is smaller than a total opening area of ​​the plurality of flow paths; and (b) a supplying step of supplying the coating liquid to each of the plurality of flow paths formed in the supply pipe portion after the preparation step, so that the plurality of coating liquids are mixed in the internal space of the mixing nozzle portion from the outlet of the supply pipe portion, One of the plurality of flow paths is a flow path for the main agent to flow, Another flow path among the plurality of flow paths is a flow path for a curing agent to flow, The main agent and the curing agent are mixed in the internal space of the mixing nozzle. The internal space includes a base end side space, a middle space and a front end side space. The outer diameter of the base end side space is set to be the same as the outer diameter of the supply tube part. The base end side space extends from the outlet side end of the supply pipe portion toward the downstream in the flow direction of the coating liquid. The intermediate space is formed in a shape that gradually narrows from the base end side space toward the front end side space.

10. The coating liquid mixing method according to claim 9, characterized in that: In the preparation step (a), a supply pipe is prepared, wherein the plurality of flow paths of the supply pipe include: a central flow path; and an annular flow path surrounding the central flow path in a circumferential direction, and the outlet of the mixing nozzle is arranged coaxially with the central axis of the central flow path. In the supplying step (b), different coating liquids are supplied to the central flow path and the annular flow path, respectively, and the flow rate of the coating liquid flowing in the annular flow path is set to be higher than the flow rate of the coating liquid flowing in the central flow path.

11. The coating liquid mixing method according to claim 9, characterized in that: In the preparation step (a), a supply pipe is prepared, wherein the plurality of flow paths of the supply pipe include: a central flow path; and an annular flow path surrounding the central flow path in a circumferential direction, and the outlet of the mixing nozzle is arranged coaxially with the central axis of the central flow path. In the supplying step (b), the viscosity of the coating liquid supplied to the annular flow path is set to be lower than the viscosity of the coating liquid supplied to the central flow path.

12. The coating liquid mixing method according to claim 9, characterized in that: In the preparation step (a), a supply pipe is prepared, wherein the plurality of flow paths of the supply pipe include: a central flow path; and an annular flow path surrounding the central flow path in a circumferential direction, and the outlet of the mixing nozzle is arranged coaxially with the central axis of the central flow path. In the supplying step (b), a coating liquid serving as a main agent is supplied to the annular flow path, and a curing agent for curing the main agent is supplied to the central flow path.

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