Painting equipment
The coating apparatus with multiple spray guns and connecting lines equalizes paint discharge, addressing uneven coating issues by using a single pump, ensuring efficient and uniform coating of large areas.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- KURIMOTO LTD
- Filing Date
- 2024-12-18
- Publication Date
- 2026-06-30
Smart Images
Figure 2026106691000001_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to a coating apparatus.
Background Art
[0002] Conventionally, when coating the surface of a pipe (for example, the outer surface of a pipe), coating is often performed using a coating apparatus including one pump and one spray gun connected to this pump. An example thereof is disclosed in Patent Document 1.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] When coating a large coating area, in order to improve the coating efficiency, it is desirable to perform coating using a plurality of spray guns.
[0005] However, when coating using a plurality of spray guns, it has been difficult to make the discharge amounts from each spray gun the same. Specifically, when using a coating apparatus in which paint is supplied from one pump to a plurality of hoses and one spray gun is connected to the tip of each hose, the number of pumps can be suppressed to one. However, in such an apparatus, the discharge pressures of the paint from the plurality of spray guns may not be equal. As a result, the discharge amounts of the paint from the plurality of spray guns may not be equal. When the discharge amounts from the plurality of spray guns are not equal, there is a problem that coating unevenness occurs.
[0006] Therefore, in view of such problems, an object of the present invention is to provide a coating apparatus capable of making the discharge amounts of paint from each spray gun equal in a coating apparatus including a plurality of spray guns. [Means for solving the problem]
[0007] The painting apparatus according to the present invention comprises a plurality of spray guns, a pump, a plurality of supply lines that supply paint pumped from the pump to each of the plurality of spray guns, and connecting lines that connect the plurality of spray guns to each other or to the plurality of supply lines to each other. [Effects of the Invention]
[0008] According to the present invention, it is possible to provide a painting apparatus equipped with multiple spray guns that can equalize the amount of paint discharged from each spray gun. [Brief explanation of the drawing]
[0009] [Figure 1] This diagram schematically shows an example of a painting apparatus according to one embodiment of the present invention, illustrating the process of the painting apparatus performing painting. [Figure 2] This figure schematically shows an example of a painting apparatus according to one embodiment of the present invention. [Figure 3] Figure 1 schematically illustrates the painting process performed by the painting apparatus shown, and is a view of the pipe being painted from the axial direction. [Figure 4] This is a schematic cross-sectional view showing an example of a spray gun in a painting apparatus according to one embodiment of the present invention. [Figure 5] Figure 2 schematically shows how paint flows from the supply pipeline to the return pipeline in the painting apparatus shown. [Figure 6] Figure 2 schematically shows how paint flows from the supply pipe to the spray gun in the painting apparatus shown. [Figure 7] This diagram schematically shows another example of a painting apparatus according to one embodiment of the present invention, and illustrates an example in which a connecting pipeline connects multiple supply pipelines to each other. [Figure 8]This diagram schematically shows another example of a painting apparatus according to one embodiment of the present invention, in which the connecting pipe also serves as part of the return pipe. [Figure 9] This diagram schematically shows another example of a painting apparatus according to one embodiment of the present invention, in which a pump is connected to each of a plurality of supply lines. [Modes for carrying out the invention]
[0010] A painting apparatus according to one embodiment of the present invention will be described below with reference to the drawings. Note that the embodiments shown below are merely examples, and the painting apparatus according to the present invention is not limited to these embodiments.
[0011] A painting apparatus according to one embodiment of the present invention (hereinafter sometimes referred to as "this painting apparatus") comprises a plurality of spray guns, a pump, a plurality of supply lines that supply paint pumped from the pump to each of the plurality of spray guns, and a connecting line that connects the plurality of spray guns to each other or to the plurality of supply lines to each other. This configuration has the advantage that, in a painting apparatus equipped with a plurality of spray guns, it is possible to make the amount of paint discharged from each spray gun equal.
[0012] The painting apparatus 1 according to this embodiment, shown in Figures 1 and 2, is a device that paints a target object T by spraying paint onto the target object T. The type of target object T is not particularly limited, but for example, it is a pipe such as a cylindrical member. The painting apparatus 1 is equipped with a plurality of spray guns 2, as will be described later (for convenience, only one spray gun 2 is shown in Figure 1). Therefore, the painting apparatus 1 can efficiently paint a large painting area. Accordingly, for example, it can efficiently paint a pipe with a large diameter. The diameter (outer diameter) of the pipe is not particularly limited, but for example, it is 900 mm or more and 2000 mm or less. In the following, the case where the target object T is a pipe (hereinafter also referred to as pipe T) (more precisely, the case where the target object T is the surface of a pipe) will be used as an example.
[0013] As shown in Figure 2, the painting apparatus 1 may include a plurality of spray guns 2, a pump 3, a plurality of supply lines 4 that supply paint pumped from the pump 3 to each of the plurality of spray guns 2, and connecting lines 5 that connect the plurality of spray guns 2 to each other. The number of spray guns 2 and the number of supply lines 4 are not particularly limited as long as there are multiples. In the example shown in Figure 2, the number of spray guns 2 and the number of supply lines 4 are two each, but there may be three or more each. One supply line 4 is connected to each spray gun 2. That is, in the painting apparatus 1, although not particularly limited, the number of spray guns 2 and the number of supply lines 4 may be the same. When the object to be painted T is a pipe, the plurality of spray guns 2 are arranged, for example, on the outside of the pipe T, in a line in the circumferential direction of the pipe T (see Figure 3). With this configuration, even pipes with large diameters can be painted efficiently.
[0014] In this embodiment, the painting apparatus 1 further comprises a paint tank 6. In this embodiment, the painting apparatus 1 further comprises a pipeline 7. In this embodiment, the painting apparatus 1 further comprises a heater 8 and a return pipeline 9. In this embodiment, the painting apparatus 1 further comprises a moving mechanism 10.
[0015] The spray gun 2 has the function of spraying paint. By spraying paint, the spray gun 2 can perform spray painting on the object to be painted T. The spray gun 2 is not particularly limited as long as it is a gun having a nozzle 211, a paint inlet 214 for connecting the supply pipe 4 to the spray gun 2, and a connection port 216 for connecting the connecting pipe 5 to the spray gun 2. The type of spray gun 2 is not particularly limited, but in this embodiment it is an airless spray gun. The airless spray gun 2 sprays paint pressurized by the pump 3 in a mist from the nozzle 211 (see Figure 4) of the spray gun 2.
[0016] In this embodiment, as shown in FIG. 2, the spray gun 2 is connected to the pump 3 via the supply pipeline 4. The supply pipeline 4 is connected to the paint tank 6 via the pump 3. The supply pipeline 4 supplies the paint sucked up by the pump 3 from the paint tank 6 to the spray gun 2. The spray gun 2 sprays the paint supplied from the supply pipeline 4.
[0017] Note that in this specification, the front-rear direction of the spray gun 2 is referred to as the "front-rear direction D1" (see FIG. 4). The front-rear direction D1 is the axial direction of the spray gun 2. The side where the air outlet 211 is provided (the side where the paint is sprayed) is defined as the front side, and the side opposite to the air outlet 211 is defined as the rear side.
[0018] In this embodiment, as shown in FIG. 4, the spray gun 2 includes a gun body 21, a needle 22, a piston 23, and a spring 24. The gun body 21 is formed in a cylindrical shape and receives the paint pumped from the pump 3 through the supply pipeline 4. The gun body 21 sprays the received paint from the air outlet 211.
[0019] In the example shown in FIG. 4, the gun body 21 has an air outlet 211, a paint chamber 212, an air chamber 213, a paint inlet 214, an air inlet 215, a connection port 216, and a needle insertion hole 217.
[0020] The air outlet 211 is an opening located at the front end of the gun body 21. The air outlet 211 sprays the pressurized paint forward. The air outlet 211 communicates with the paint inlet 214 through the paint chamber 212.
[0021] The paint chamber 212 communicates with the downstream end 43 of the supply pipeline 4 through the paint inlet 214. The paint chamber 212 is filled with the paint supplied from the supply pipeline 4. The front part of the paint chamber 212 has a reduced diameter and the tip is formed in a substantially conical shape or a substantially truncated conical shape and is connected to the air outlet 211.
[0022] The air chamber 213 is in communication with the air inlet 215. The air inlet 215 is connected to an air supply source (not shown) via a pipeline (not shown). Air from the air supply source is supplied to the air chamber 213 through the air inlet 215.
[0023] The needle insertion hole 217 is a hole that penetrates the partition wall 218 separating the paint chamber 212 and the air chamber 213. A needle 22 extending in the front-rear direction D1 is slidably inserted through the needle insertion hole 217. Airtightness and liquid tightness are ensured between the needle insertion hole 217 and the needle 22.
[0024] The connection port 216 communicates with the paint chamber 212. One end of the connecting pipe 5 is connected to the connection port 216. The connection port 216 communicates with the connection port 216 of other spray guns 2 through the connecting pipe 5. As a result, the paint chamber 212 communicates with the paint chamber 212 of other spray guns 2 through the connecting pipe 5. By communicating the paint chambers 212 of multiple spray guns 2 with each other, it is possible to suppress the occurrence of a pressure difference in the paint between the paint chambers 212 of multiple spray guns 2, as will be described later.
[0025] The needle 22 is provided so as to be movable in the forward / backward direction D1 within the paint chamber 212 and the air chamber 213. A substantially spherical valve body 221 is provided at the tip of the needle 22. By moving the needle 22 in the forward / backward direction D1, the valve body 221 moves toward and away from the substantially conical or substantially frustoconical tip of the paint chamber 212, thereby adjusting the opening of the outlet 211 and thus adjusting the amount of paint discharged from the outlet 211. Specifically, for example, by moving the needle 22 forward and bringing the valve body 221 at its tip closer to the outlet 211, the discharge amount can be reduced. Also, by moving the needle 22 forward and blocking the outlet 211 with the valve body 221 at its tip, the discharge of paint can be stopped. Also, by moving the needle 22 backward and moving the valve body 221 at its tip further away from the outlet 211, the discharge amount can be increased.
[0026] The spring 24 biases the piston 23, which is located at the rear end of the needle 22, to press forward. When air is supplied to the air chamber 213 and the air pressure in the air chamber 213 becomes greater than the elastic force of the spring 24, the piston 23 moves backward, and consequently, the needle 22 moves backward. When the supply of air to the air chamber 213 is stopped and the air pressure in the air chamber 213 becomes less than the elastic force of the spring 24, the piston 23 moves forward, and consequently, the needle 22 moves forward.
[0027] As shown in Figure 2, the supply pipeline 4 has its downstream end 43 connected to the spray gun 2 and its upstream end connected to the pump 3. In the example shown in Figure 2, the upstream end of the supply pipeline 4 is connected to the pump 3 via a single pipeline 7. Specifically, in the example shown in Figure 2, the painting apparatus 1 includes only one pump 3 and one pipeline 7 that supplies paint from the pump 3 to multiple supply pipelines 4. The multiple supply pipelines 4 are pipelines that branch off from the downstream end of the single pipeline 7. By branching multiple supply pipelines 4 from the downstream end of the single pipeline 7, it is possible to connect one pump 3 to multiple supply pipelines 4, thus limiting the number of pumps 3 to one. In other words, with the above configuration, even if the painting apparatus does not have multiple pumps 3 but only one, it has the advantage of being able to pump paint to multiple spray guns 2. In this painting apparatus 1, as shown in Figure 2, each upstream end of the multiple supply lines 4 may be connected at a single point (the same point) to the end of a single line 7. In this specification, this connection point may be referred to as the connection portion 45 between the supply line 4 and the single line 7. That is, the connection portion 45 between the supply line 4 and the single line 7 is the same location as the upstream end of the supply line 4, and the connection portion 45 between the supply line 4 and the single line 7 and the pump 3 are connected by the single line 7.
[0028] In this painting apparatus 1, the supply pipe 4 may be a flexible pipe or a rigid pipe.
[0029] When the object to be painted T is a pipe (more precisely, the surface of the pipe), it is preferable that the multiple supply lines 4 in this painting apparatus 1 are flexible. With this configuration, when painting is performed while moving the spray gun 2 along the circumferential direction and / or axial direction of the pipe, the supply lines 4 can be flexibly deformed to follow the movement of the spray gun 2. Specifically, for example, the supply lines 4 can change the direction of curvature and curvature to follow the movement of the spray gun 2. Therefore, the surface of the pipe (for example, the outer surface) can be painted easily and smoothly. Furthermore, with this configuration, the supply lines 4 can be wound in a spiral shape or the like (see Figure 1), so that the wound supply lines 4 and the spray gun 2 can be connected without taking up much space.
[0030] The supply conduit 4 can be made of, for example, soft rubber, synthetic resin, etc. The supply conduit 4 is, for example, a flexible hose. The length of the supply conduit 4 is not particularly limited as long as it can supply the paint pressurized by the pump 3 to the spray gun 2. In this embodiment, the painting apparatus 1 is used to paint a large-diameter and / or long pipe T (see Figure 1), and the length of the supply conduit 4 is, for example, about 50 m.
[0031] It is preferable that the supply conduit 4 moves in accordance with the movement of the spray gun 2, so as to follow the spray gun 2. If multiple supply conduits 4 are flexible, the multiple supply conduits 4 may deform as they follow the spray gun 2. For example, when multiple supply conduits 4 follow the spray gun 2, they may bend and / or their cross-section (cross-section in a direction perpendicular to the axial direction) may deform from a circular to an elliptical shape. The resistance of the paint flowing through the supply conduit 4 may differ between the state in which the supply conduit 4 maintains its original shape (hereinafter also referred to as the "original state"; for example, a state in which it extends in a substantially straight line and has a circular cross-section) and the state in which it has deformed from its original shape (hereinafter also referred to as the "deformed state"; for example, a state in which it is curved and / or has an elliptical cross-section). If the resistance differs, the pressure of the flowing paint may differ between the original state and the deformed state.
[0032] The connecting pipeline 5 of this painting apparatus is preferably a pipeline that connects multiple spray guns 2 to each other. In other words, it is preferable that the connecting pipeline 5 is connected to multiple spray guns 2 as shown in Figure 2. With this configuration, compared to the case where the connecting pipeline 5 connects multiple supply pipelines 4 to each other, it is possible to make the discharge pressure of the paint from each spray gun more precisely equal, and thus has the advantage of making the discharge amount of paint from each spray gun equal. Specifically, as shown in Figure 4, it is preferable that the connecting pipeline 5 is in communication with the connection port 216 of the spray gun 2. As a result, the paint chamber 212 is in communication with the paint chamber 212 of the other spray gun 2 through the connecting pipeline 5. By having the paint chambers 212 of multiple spray guns 2 communicate with each other, it is possible to suppress the occurrence of a pressure difference in the paint between the paint chambers 212 of multiple spray guns 2. Specifically, for example, consider the case where the pressure of the paint supplied to the paint chamber 212 of one spray gun 2 is higher than the pressure of the paint supplied to the paint chamber 212 of the other spray gun 2. In this case, due to the pressure difference of the paint, paint flows from the paint chamber 212 of one spray gun 2 to the paint chamber 212 of the other spray gun 2. As a result, the pressure difference of the paint between the paint chamber 212 of one spray gun 2 and the paint chamber 212 of the other spray gun 2 is absorbed by the flow of paint. Therefore, the occurrence of a pressure difference of paint between the paint chambers 212 of the multiple spray guns 2 is suppressed. The configuration of the connecting pipe 5 is not particularly limited as long as it can deliver the paint pumped by the pump 3. For example, the connecting pipe 5 may or may not be flexible.
[0033] The painting apparatus 1 further comprises a heater 8 provided between a plurality of supply lines 4 and a pump 3 to heat the paint, and a return line 9 to return the paint to the paint tank 6 that supplies the paint to the pump 3. The upstream end of the return line 9 may be connected to a plurality of supply lines 4 or a plurality of spray guns 2. With this configuration, a paint tank 6, pump 3, heater 8, plurality of supply lines 4, and return line 9 are provided, and a circulation path for heated paint is formed, which has the advantage that paint with a viscosity suitable for painting can be sprayed from the spray gun 2.
[0034] The heater 8 (see Figures 1 and 2) is a device for heating the paint. By heating the paint with the heater 8, the paint temperature can be adjusted so that the viscosity of the paint is suitable for painting. In the example shown in Figures 1 and 2, the painting apparatus 1 is equipped with one heater 8. The heater 8 is installed between the upstream end of the multiple supply lines 4 (i.e., the connection point 45 between the supply lines 4 and one line 7) and the pump 3. Specifically, the heater 8 is installed in the middle of one line 7. This allows the paint supplied to the multiple supply lines 4 to be heated by a single heater 8, and the number of heaters 8 can be reduced to one.
[0035] The return pipeline 9 (see Figures 1 and 2) is a pipeline that returns paint from multiple supply pipelines 4 or multiple spray guns 2 to the paint tank 6. In the example shown in Figures 1 and 2, the upstream end of the return pipeline 9 is connected to the multiple supply pipelines 4. By providing the return pipeline 9, the paint supplied to the multiple supply pipelines 4 can be returned to the paint tank 6. The method of connecting the multiple supply pipelines 4 and the return pipeline 9 is not particularly limited as long as it is a connection method that allows the paint supplied from the pump 3 to the multiple supply pipelines 4 to be returned to the paint tank 6 and then supplied again from the pump 3 to the multiple supply pipelines 4, that is, a connection method that allows the paint to be circulated. The paint supplied to the multiple supply pipelines 4 is heated by the heater 8. Therefore, heated paint is returned to the paint tank 6. As the heated paint is returned to the paint tank 6, the heated paint is sucked up by the pump 3. This forms a circulation path having the paint tank 6, pump 3, heater 8, multiple supply pipelines 4, and return pipeline 9. In this circulation path, heated paint is circulated. Therefore, the spray gun 2 can spray paint that has been heated and has a viscosity suitable for painting.
[0036] In the examples shown in Figures 1 and 2, the upstream end of the return pipeline 9 is connected to the supply pipeline 4. In the examples shown in Figures 5 and 6, a directional control valve 91 is provided at the connection point 41 (hereinafter sometimes referred to as "connection point 41") between the supply pipeline 4 and the return pipeline 9 to switch the direction in which the paint flows. The directional control valve 91 can switch between a state in which the paint pumped from the upstream side of the supply pipeline 4 to the connection point 41 flows into the return pipeline 9 (see Figure 5), and a state in which the paint pumped from the upstream side of the supply pipeline 4 to the connection point 41 flows toward the downstream end 43 of the supply pipeline 4 (i.e., toward the spray gun 2) (see Figure 6). The directional control valve 91 is, for example, a three-way valve (see Figures 5 and 6). In the example shown in Figure 5, the direction of the directional control valve 91 is set to direct all the paint pumped from the upstream side of the supply pipeline 4 to the connection section 41 into the return pipeline 9. In the example shown in Figure 6, the directional control valve 91 is set to direct all the paint pumped from the upstream side of the supply pipeline 4 to the connection section 41 towards the downstream end 43 of the supply pipeline 4 (i.e., towards the spray gun 2). However, it is not limited to these settings. For example, the directional control valve 91 may be switched to direct a portion of the paint pumped from the upstream side of the supply pipeline 4 to the connection section 41 towards the spray gun 2, and the remaining portion of the paint into the return pipeline 9.
[0037] In the examples shown in Figures 1 and 2, the painting apparatus 1 is further equipped with a flow control valve 92 that adjusts the flow rate of the return pipeline 9. High-pressure paint, pumped by the pump 3, flows through the return pipeline 9. However, by providing the flow control valve 92, the flow rate of paint returned from the return pipeline 9 to the paint tank 6 can be reduced. Therefore, splashing of paint returned into the paint tank 6 can be suppressed.
[0038] Furthermore, the painting apparatus 1 may further include a moving mechanism 10. In the example shown in Figure 1, the moving mechanism 10 (see Figure 1) is configured to move at least one of the plurality of spray guns 2 and the tube T relative to the tube T in the axial and / or circumferential direction. In the example shown in Figure 1, the moving mechanism 10 is configured to move the plurality of spray guns 2 along the tube T (specifically, along the axial direction of the tube T). The moving mechanism 10 includes a guide portion 101 extending along the axial direction of the tube T, a moving portion 102 that moves guided by the guide portion 101, and a drive unit (not shown) that moves the moving portion 102. The spray guns 2 are attached to the moving portion 102. The moving mechanism 10 is also configured to rotate the tube T in the circumferential direction of the tube T. Specifically, the moving mechanism 10 includes a rotating roller 103 that rotates the tube T around the tube axis, and a drive unit (not shown) that rotates the rotating roller 103. The rotating roller 103 is positioned to support the pipe body T. By rotating the rotating roller 103 with the pipe body T placed on it, the pipe body T rotates around its axis. While the pipe body T is rotating, the movable part 102 is moved in the axial direction of the pipe body T, and paint is sprayed from the spray gun 2, allowing the spray gun 2 to paint while moving spirally relative to the pipe body T.
[0039] Next, the operation of the painting apparatus 1 will be explained with reference to Figures 1 to 6. Note that the operation described below is an example and is not limited to this example.
[0040] First, we will explain the case where the painting apparatus 1 does not have a heater 8 and a return pipe 9. For convenience, in this explanation, we will assume that the heater 8, the return pipe 9, and the directional control valve 91 are absent in Figures 1 and 2. In this case, first, the pump 3 (see Figures 1 and 2) draws up the paint from the paint tank 6. The pump 3 pressurizes the drawn-up paint and flows the pressurized paint towards the supply pipe 4. In the example shown in Figure 2, the pump 3 flows the paint into one pipe 7. The paint flows from one pipe 7 into two supply pipes 4. The paint flowing through the supply pipes 4 flows into the spray gun 2 (see Figure 4). The paint that flows into the spray gun 2 flows into the paint chamber 212 and the connection port 216. The paint that flows into the connection port 216 flows into the connecting pipe 5.
[0041] Let's consider a case where the pressure of the paint supplied to the paint chamber 212 of one spray gun 2 is higher than the pressure of the paint supplied to the paint chamber 212 of another spray gun 2. In this case, paint flows from the paint chamber 212 of one spray gun 2 to the paint chamber 212 of the other spray gun 2 via the connecting pipe 5. As a result, the pressure difference of the paint between the paint chamber 212 of one spray gun 2 and the paint chamber 212 of the other spray gun 2 is absorbed by the flow of paint. Therefore, the occurrence of a pressure difference of paint between the paint chambers 212 of multiple spray guns 2 is suppressed.
[0042] When air is supplied to the air chamber 213 and the air pressure in the air chamber 213 becomes greater than the elastic force of the spring 24, the piston 23 moves backward, and consequently, the needle 22 also moves backward. This moves the valve body 221 at the tip of the needle 22 away from the outlet 211, allowing paint to be sprayed from the outlet 211. As described above, the occurrence of pressure differences in the paint between the paint chambers 212 of the multiple spray guns 2 is suppressed. As a result, the paint pressure between the paint chambers 212 of the multiple spray guns 2 is made approximately uniform. In this state, when paint is sprayed from the multiple spray guns 2, the flow rates of the paint from the multiple spray guns 2 become approximately equal (approximately uniform). Therefore, painting of the pipe T can be performed efficiently using multiple spray guns 2, and the pipe T can be painted without unevenness. Furthermore, the number of pumps 3 can be reduced to one, which reduces the manufacturing and maintenance costs of the painting apparatus 1.
[0043] Next, we will describe the case where the painting apparatus 1 is equipped with a heater 8 and a return pipeline 9. In this case, first, the pump 3 (see Figures 1 and 2) draws up the paint from the paint tank 6. The painting apparatus 1 heats the paint with the heater 8 to make the paint viscosity suitable for painting, and circulates the heated paint in a circulation path that includes a part of the supply pipeline 4 and the return pipeline 9. Specifically, first, as shown in Figure 5, the direction of the flow path of the directional control valve 91 is adjusted. The flow path of the directional control valve 91 is set so that all of the paint that has been pressurized from the upstream side of the supply pipeline 4 to the connection part 41 flows into the return pipeline 9. With the direction of the flow path of the directional control valve 91 set in this way, the pump 3 draws up the paint from the paint tank 6. The pump 3 pressurizes the drawn-up paint and flows the pressurized paint toward the supply pipeline 4. In the example shown in Figure 2, the pump 3 flows the paint into one pipeline 7. Heater 8 heats the paint flowing through one pipe 7. The heated paint flows into two supply pipes 4. The paint flowing through supply pipes 4 flows into return pipe 9 via a directional control valve 91. The flow rate of the paint flowing through return pipe 9 is adjusted by a flow control valve 92 and returned to paint tank 6. The paint that has returned to paint tank 6 is then drawn up again by pump 3. In this way, the paint can circulate through the circulation path while being heated by heater 8. By circulating through the circulation path, the paint is efficiently heated and brought to a state with a temperature and viscosity suitable for painting.
[0044] Next, the painting apparatus 1 paints the pipe T (see Figure 1). Specifically, first, as shown in Figure 6, the direction of the flow path of the directional control valve 91 is adjusted. The flow path of the directional control valve 91 is set so that all of the paint pumped from the upstream side of the supply line 4 to the connection part 41 flows to the spray gun 2. With the direction of the flow path of the directional control valve 91 set in this way, the pump 3 draws up the paint from the paint tank 6. The pump 3 pressurizes the drawn-up paint and flows the pressurized paint toward the supply line 4. In the example shown in Figure 2, the pump 3 flows the paint into one line 7. The heater 8 heats the paint flowing through one line 7. The heated paint flows into the two supply lines 4. The paint flowing through the supply lines 4 flows into the spray gun 2 (see Figure 4) via the directional control valve 91. The paint that flows into the spray gun 2 flows into the paint chamber 212 and the connection port 216. The paint that flows into the connection port 216 flows into the connecting pipe 5. From this point onward, the procedure is the same as when the painting apparatus 1 is not equipped with a heater 8 and a return pipe 9. Even when the painting apparatus 1 is equipped with a heater 8 and a return pipe 9, the pressure difference of the paint between the paint chambers 212 of the multiple spray guns 2 is suppressed. Therefore, painting of the pipe T can be performed efficiently by multiple spray guns 2, and the pipe T can be painted without unevenness. In addition, by returning the paint heated by the heater 8 to the paint tank and circulating it in the circulation path, the temperature and viscosity of the paint can be efficiently brought to a state suitable for painting.
[0045] In the example shown in Figure 1, the connecting pipeline 5 is a pipeline that connects multiple spray guns 2, but it is not limited to this. For example, in the example shown in Figure 7, the connecting pipeline 5 is a pipeline that connects multiple supply pipelines 4. The connecting pipeline 5 connects the intermediate sections of the multiple supply pipelines 4 that are located upstream of the downstream end 43. This allows the intermediate sections of the multiple supply pipelines 4 to communicate with each other. By allowing the intermediate sections of the multiple supply pipelines 4 to communicate with each other, it is possible to suppress the occurrence of a pressure difference in paint between the portions 44 of the multiple supply pipelines 4 that are downstream of the connection point 42 with the connecting pipeline 5. Specifically, for example, consider a case where the pressure of paint upstream of the connection point 42 with the connecting pipeline 5 in one supply pipeline 4 is higher than the pressure of paint upstream of the connection point 42 with the connecting pipeline 5 in another supply pipeline 4. In this case, due to the pressure difference of the paint, paint flows from one supply pipeline 4 to another supply pipeline 4 via the connecting pipeline 5. As a result, the pressure difference of the paint between the portion 44 downstream of the connection point 42 with the connecting pipe 5 in one supply pipe 4 and the portion 44 downstream of the connection point 42 with the connecting pipe 5 in another supply pipe 4 is absorbed by the flow of paint through the connecting pipe 5. Therefore, the occurrence of pressure differences of the paint between the portions 44 downstream of the connection point 42 with the connecting pipe 5 in multiple supply pipes 4 is suppressed.
[0046] In the example shown in Figure 7, the upstream end of the return pipeline 9 is connected to multiple spray guns 2. Specifically, for example, the upstream end of the return pipeline 9 is connected to the connection port 216 shown in Figure 4, instead of the connection pipeline 5. This allows the paint that has flowed into the spray guns 2 to be returned to the paint tank 6 via the return pipeline 9.
[0047] Furthermore, in the example shown in Figure 7, a directional control valve (not shown) may be provided inside the spray gun 2 to switch the direction in which the paint flows. This directional control valve can switch between a state in which the paint that has reached the spray gun 2 from the downstream side of the supply pipeline 4 flows into the return pipeline 9, and a state in which the paint that has reached the spray gun 2 from the downstream side of the supply pipeline 4 flows to the outlet 211. This directional control valve is, for example, a three-way valve.
[0048] As shown in the example in Figure 7, the connecting pipeline 5 is a pipeline that connects multiple supply pipelines 4, and it is preferable that the length L1 (hereinafter also referred to as the first length L1) of the supply pipeline 4 from the connection point 42 with the connecting pipeline 5 to the end 43 on the spray gun 2 side is approximately equal among the multiple supply pipelines 4. This configuration has the advantage that the discharge pressure of paint from each spray gun can be made equal, and therefore the amount of paint discharged from each spray gun can be made equal. In this specification, the concept of "the first length L1 being approximately equal among multiple supply pipelines 4" includes not only the case where the first length L1 is equal among multiple supply pipelines 4, but also the case where the first length L1 is slightly different among multiple supply pipelines 4. For example, the first length L1 in one supply pipeline 4 is 90% to 110%, preferably 95% to 105%, of the first length L1 in the other supply pipelines 4. From the viewpoint of equalizing the amount of paint discharged from each spray gun by equalizing the paint discharge pressure from each spray gun, it is preferable that the first length L1 is equal among the multiple supply lines 4. That is, it is preferable that the first length L1 in one supply line 4 is 100% of the length of the first length L1 in the other supply lines 4. In the example shown in Figure 7, there are two supply lines 4. In this case, the first length L1 is approximately equal between the two supply lines 4.
[0049] As described above, the supply line 4 is flexible and moves in accordance with the movement of the spray gun 2. Therefore, multiple supply lines 4 may deform when following the spray gun 2. However, if the first length L1 of the supply line 4 is approximately equal among multiple supply lines 4, even if the portion of the supply line 4 corresponding to the first length L1 deforms in accordance with the movement of the spray gun 2, the pressure of the paint supplied from the supply line 4 to the spray gun 2 can be made approximately equal among multiple supply lines 4. In detail, as described above, by connecting multiple supply lines 4 with connecting lines 5, the occurrence of a pressure difference in paint between the portions 44 of the multiple supply lines 4 downstream of the connection point 42 with the connecting line 5 is suppressed. Furthermore, even if the supply line 4 deforms in accordance with the movement of the spray gun 2, if the first length L1 in the supply line 4 is approximately equal among multiple supply lines 4, the pressure difference between the downstream ends 43 of the multiple supply lines 4 is likely to be smaller compared to the case where the first length L1 differs among multiple supply lines 4. This is because the smaller the difference in the first length L1 among the multiple supply lines 4, the smaller the sum of the pressure differences in the paint due to the deformation of the portion 44 corresponding to the first length L1 in the multiple supply lines 4 (the sum in the longitudinal direction of the supply line 4). Therefore, the pressure difference in the paint between the downstream ends 43 of the multiple supply lines 4 can be further suppressed.
[0050] Furthermore, as shown in the example in Figure 7, the connecting pipeline 5 is a pipeline that connects multiple supply pipelines 4 together, and it is preferable that the length L1 (first length) from the connection point 42 with the connecting pipeline 5 in the supply pipeline 4 to the downstream end 43 of the supply pipeline 4 is shorter than the length L2 (hereinafter also referred to as the second length L2) of the supply pipeline 4 from the connection point 42 to the pump-side end (i.e., the connection point 45 between the supply pipeline 4 and one pipeline 7). This configuration has the following advantages compared to the case where the first length L1 is longer than the second length L2. That is, even if the supply pipeline 4 deforms in accordance with the movement of the spray gun 2, the pressure of the paint supplied from the supply pipeline 4 to the spray gun 2 can be made more stably equal among the multiple supply pipelines 4. In detail, as described above, by connecting multiple supply pipelines 4 together with the connecting pipeline 5, it is possible to suppress the occurrence of a pressure difference in the paint between the portions 44 downstream of the connection point 42 with the connecting pipeline 5 in the multiple supply pipelines 4. Even if the supply line 4 deforms in response to the movement of the spray gun 2, if the first length L1 in the supply line 4 is shorter than the second length L2, the pressure difference between the downstream ends 43 of the multiple supply lines 4 is likely to be smaller compared to the case where the first length L1 is longer than the second length L2. This is because the smaller the first length L1 in the supply line 4, the smaller the sum of the pressure differences in the paint due to the deformation of the portion 44 corresponding to the first length L1 in the multiple supply lines 4 (the sum in the longitudinal direction of the supply line 4). Therefore, the pressure difference in the paint between the downstream ends 43 of the multiple supply lines 4 can be further suppressed. For example, the first length L1 is 1% or less of the total length of the supply line 4, preferably 0.5% or less. Specifically, for example, if the total length of the supply line 4 is about 50m, the first length L1 is 0.5m or less, preferably 0.25m or less.
[0051] Furthermore, in the example shown in Figure 7, the connecting pipeline 5 connects the end regions on the spray gun 2 side of multiple supply pipelines 4. In this specification, "end region on the spray gun 2 side of the supply pipeline 4" is a concept that includes not only the end of the supply pipeline 4 on the spray gun 2 side, but also the vicinity of the end of the supply pipeline 4 on the spray gun 2 side. The tip of the end region on the spray gun 2 side of the supply pipeline 4 is supported by the spray gun 2. Therefore, even if the supply pipeline 4 follows the movement of the spray gun 2, the end region on the spray gun 2 side of the supply pipeline 4 is less affected by the movement of the spray gun 2 in terms of shape, and is considered to undergo little deformation (bending and / or change in cross-sectional shape, etc.). Consequently, even if the supply pipeline 4 follows the movement of the spray gun 2, the occurrence of a pressure difference in paint between the portions 44 downstream of the connection point 42 with the connecting pipeline 5 in multiple supply pipelines 4 is suppressed.
[0052] Furthermore, the end region of the supply pipeline 4 on the spray gun 2 side (i.e., the downstream side) may be reinforced with a reinforcing member (not shown) to further suppress deformation caused by the movement of the spray gun 2. For example, a reinforcing member may be attached to the outer circumferential surface of the end region of the supply pipeline 4 on the spray gun 2 side.
[0053] In the example shown in Figure 7, the connecting pipeline 5 and the return pipeline 9 are provided separately, but this is not the only option. For example, as shown in Figure 8, the portion of the return pipeline 9 that connects multiple supply pipelines 4 may be shared as the connecting pipeline 5. In this case, for example, a directional control valve (not shown) is provided inside the spray gun 2. This directional control valve is configured to switch the direction in which paint flows inside the spray gun 2. Specifically, this directional control valve is configured to switch between a state in which the paint supplied from the supply pipeline 4 to the spray gun 2 flows to the discharge port and not to the connecting pipeline 5 and the return pipeline 9, and a state in which the paint supplied from the supply pipeline 4 to the spray gun 2 flows to the connecting pipeline 5 and the return pipeline 9 and not to the discharge port. Therefore, by adjusting the direction of paint flow with the directional control valve, when painting is performed by the painting apparatus 1, paint can be discharged from the discharge port of the spray gun 2 and the return of paint to the paint tank 6 can be stopped. Furthermore, when the paint heated by the heater 8 is returned to the paint tank 6 and the paint is circulated through the supply line 4 and the return line 9, the discharge of paint from the nozzle of the spray gun 2 can be stopped, and the paint can be returned to the paint tank 6.
[0054] Furthermore, in the example shown in Figure 2, the painting apparatus 1 supplies paint from one pump 3 to multiple supply lines 4, but it is not limited to this. For example, as shown in Figure 9, the painting apparatus 1 may be configured to supply paint from one pump 3 to one supply line 4. In this case, the number of pumps 3 and heaters 8 will be multiple, but the amount of paint discharged from multiple spray guns 2 can be made approximately equal. [Explanation of symbols]
[0055] 1. Painting equipment 2 spray guns 21 Gun body 211 Air outlet 212 Paint room 213 Air chamber 214 Paint Inlet 215 Air Inlet 216 connection ports 217 Needle insertion hole 218 Partition wall 22 Needles 221 Valve body 23 pistons 24 springs 3 pumps 4 Supply pipeline 41 Connection between the supply pipeline and the return pipeline 42 Connection point between supply pipeline and connecting pipeline 43 Downstream end of the supply pipeline 44. The portion of the supply pipeline downstream of the connection point with the connecting pipeline. 45 Connection between a supply pipeline and another pipeline 5. Connecting conduits 6 Paint Tanks 7. One pipeline 8 Heaters 9. Return pipeline 91 Directional control valve 92 Flow control valve 10 Moving mechanism 101 Guide Section 102 Mobile Unit 103 Rotating Roller
Claims
1. Multiple spray guns, Pump and Multiple supply lines supply paint, which is pumped from the pump, to each of the multiple spray guns. A connecting pipeline that connects the plurality of spray guns to each other, or the plurality of supply lines to each other, A painting apparatus equipped with the following features.
2. The painting apparatus according to claim 1, wherein the connecting conduit is a conduit for connecting the plurality of spray guns.
3. The aforementioned connecting pipeline is a pipeline that connects the plurality of supply pipelines to each other. The painting apparatus according to claim 1, wherein the length of the supply pipeline from the connection point with the connecting pipeline to the end on the spray gun side is substantially equal among the plurality of supply pipelines.
4. The aforementioned connecting pipeline is a pipeline that connects the plurality of supply pipelines to each other. The painting apparatus according to claim 1, wherein the length of the supply pipeline from the connection point with the connecting pipeline to the end on the spray gun side is shorter than the length of the supply pipeline from the connection point to the end on the pump side.
5. A painting apparatus for painting the surface of a pipe, The painting apparatus according to claim 1, further comprising a moving mechanism for moving at least one of the plurality of spray guns and the tube relatively along the axial and / or circumferential direction of the tube.
6. The moving mechanism is configured to move the plurality of spray guns along the axial and / or circumferential directions of the tube, The supply pipeline follows the movement of the spray gun in accordance with the movement of the spray gun. The painting apparatus according to claim 5, wherein the connecting pipeline connects the end regions on the spray gun side of the plurality of supply pipelines.
7. The aforementioned pump consists of one unit. The system further comprises one pipeline for supplying paint from the pump to the plurality of supply pipelines, The painting apparatus according to claim 1, wherein the plurality of supply pipelines are pipelines that branch off from the downstream end of one of the pipelines.
8. A heater for heating paint is provided between the aforementioned multiple supply lines and the pump, The pump further comprises a return pipeline for returning paint to a paint tank that supplies paint to the pump, The painting apparatus according to any one of claims 1 to 7, wherein the upstream end of the return pipeline is connected to the plurality of supply pipelines or the plurality of spray guns.