Electrostatic atomization device

Abstract

To provide an electrostatic atomization device which can make both the suppression of discharge and the stabilization of a liquid electrification state.SOLUTION: An electrostatic atomization device 1a related to one embodiment comprises: a liquid flow forming part 10 having a liquid flow channel 11, receiving a liquid from one end 11a of the flow channel 11, and making the liquid flow out of the other end 11b opposite to the one end 11a of the flow channel 11; and a connection electrode 20 and a relay electrode 30, as at least two electrodes arranged separated from each other, where at least a part thereof is located or faces inside the flow channel 11.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an electrostatic spraying device that sprays an electrically charged liquid onto an object to be coated. [Background technology]

[0002] There is known an electrostatic spraying device that includes a flow path forming portion having a flow path for liquid and an electrode disposed in the flow path. Such an electrostatic spraying device receives liquid from one end of the flow path of the flow path forming portion. The other end opposite to the one end of the flow path of the flow path forming portion allows the liquid to flow out.

[0003] In an electrostatic spraying device in which an electrode is disposed within the flow path as described above, for example, the negative pole of a power supply is connected to the electrode. Meanwhile, the positive pole of the power supply is connected to a target to be coated that is disposed away from the electrostatic spraying device. Then, a voltage is applied from the power supply. This generates a potential difference between the electrostatic spraying device and the target to be coated. In this state, when a liquid is passed through the flow path of the flow path forming portion, the liquid becomes electrostatically charged. This allows the charged liquid to be attracted to the target to be coated according to the potential difference.

[0004] In an electrostatic spraying device in which an electrode is disposed in a flow path, the electrode generally extends from a contact with a power source to the tip of the flow path in the flow path forming portion (corresponding to the other end described above). A nozzle may be provided in the flow path forming portion. In this case, the electrode generally extends from the contact with the power source to the tip of the nozzle.

[0005] However, as described above, the size of the electrode extending from the contact point with the power source to the tip of the flow path of the flow path forming portion is large, and in this case, discharge is likely to occur between the electrode and the object to be coated.

[0006] On the other hand, liquid spray devices that do not have electrodes arranged in the flow path are also known. For example, Patent Document 1 discloses an electrostatic spray device that includes a main body having a liquid flow path, a component having a paint chamber connected to the flow path in the main body, and a nozzle held by the component. In the electrostatic spray device of Patent Document 1, a voltage is applied to the liquid flowing through the flow path, the paint chamber, and the nozzle.

[0007] In electrostatic spraying devices that do not have electrodes disposed in the flow path, the risk of discharge is reduced. However, electricity flows entirely through the liquid in the electrostatic spraying device. In this case, the electrical resistance of the liquid in the electrostatic spraying device may become unstable depending on the state and type of the liquid. In this case, for example, there is a risk that the desired charged state of the liquid or the desired potential difference between the electrode and the object to be sprayed cannot be ensured. As a result, there is a risk that the spray state may become unstable. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] Japanese Patent Application Publication No. 2022-87679 Summary of the Invention [Problem to be solved by the invention]

[0009] Therefore, an object of the present invention is to provide an electrostatic spraying device that can suppress discharge and stabilize the charged state of the liquid at the same time. [Means for solving the problem]

[0010] The embodiments of the present disclosure relate to the following [1] to

[14] .

[0011] [1] A flow path forming portion having a flow path for a liquid, receiving the liquid from one end of the flow path and discharging the liquid from the other end opposite to the one end of the flow path; and at least two electrodes spaced apart from each other, at least a portion of which is located within or faces the flow path.

[0012] [2] The flow path forming portion includes an additional flow path connected between the one end and the other end of the flow path, and the additional flow path receives the liquid from the flow path and discharges the liquid from a downstream end thereof; The electrostatic spraying device according to [1], further comprising an additional electrode at least a portion of which is located within or faces the additional flow path.

[0013] [3] The electrostatic spraying device according to either [1] or [2], wherein the at least two electrodes are spaced apart in the direction in which the liquid flows.

[0014] [4] The electrostatic spraying device according to any one of [1] to [3], wherein the at least two electrodes include at least one electrode that is entirely located within the flow path.

[0015] [5] The electrostatic spraying device according to any one of [1] to [4], wherein the at least two electrodes include a connection electrode electrically connected to a power source.

[0016] [6] The electrostatic spraying device according to [5], wherein one of the at least two electrodes other than the connection electrode is formed from a wire.

[0017] [7] An electrostatic spraying device as described in [5], wherein one of the at least two electrodes other than the connecting electrode is formed from a tubular member or a member made by rolling up a thin plate.

[0018] [8] The electrostatic spraying device according to any one of [1] to [7], wherein at least one of the at least two electrodes is detachably provided in the flow path forming portion.

[0019] [9] An electrostatic spraying device described in any of [1] to [8], wherein the at least two electrodes include at least one electrode including an attachment portion that is held directly or indirectly to the flow path forming portion and an electrode main body portion that extends from the attachment portion along the flow path.

[0020]

[10] The electrode including the mounting portion and the electrode main body portion is formed from a wire material, The electrostatic spraying device according to [9], wherein the attachment portion is formed by forming a part of the wire into a spiral shape.

[0021]

[11] An electrostatic spraying device according to any one of [1] to

[10] , further comprising an insulating connecting member that connects adjacent electrodes of the at least two electrodes.

[0022]

[12] The flow path forming portion includes a first component having a first flow path portion that constitutes a part of the flow path, a second component having a second flow path portion that constitutes a part of the flow path, and a third component having a third flow path portion that constitutes a part of the flow path, the second component is tubular and defines the second flow path portion on its inner circumferential surface; The electrostatic spraying device described in any one of [1] to

[11] , wherein the second part connects the first part and the third part, and connects the second flow path part to the first flow path part and the third flow path part.

[0023]

[13] An electrostatic spraying device described in any of [1] to

[12] , wherein the flow path forming portion includes a main body portion having a main flow path portion that forms part of the flow path, and a nozzle provided in the main body portion that receives the liquid from the main flow path portion, and the flow path is formed by the main flow path portion and the inner peripheral portion of the nozzle.

[0024]

[14] The device further includes a power cable including a cable connected to a power source and a connector provided on the cable and detachably connected to the flow path forming portion, one electrode of the at least two electrodes is integrated into the connector; An electrostatic spraying device described in any of [1] to

[13] , wherein when the connector is connected to the flow path forming portion, a portion of the electrode integrated into the connector is positioned within or faces the flow path. [Effects of the Invention]

[0025] According to the present disclosure, it is possible to suppress discharge and stabilize the charged state at the same time. [Brief explanation of the drawings]

[0026] [Figure 1]1 is a diagram schematically illustrating a spraying system including an electrostatic spraying device according to a first embodiment. [Figure 2] 1 is a cross-sectional view showing an electrostatic spraying device according to a first embodiment. [Figure 3] FIG. 4 is a cross-sectional view showing an electrostatic spraying device according to a second embodiment. [Figure 4] FIG. 10 is a cross-sectional view showing an electrostatic spraying device according to a third embodiment. [Figure 5] FIG. 10 is a cross-sectional view showing an electrostatic spraying device according to a fourth embodiment. [Figure 6] FIG. 10 is a cross-sectional view showing an electrostatic spraying device according to a fifth embodiment. [Figure 7] FIG. 10 is a cross-sectional view showing an electrostatic spraying device according to a sixth embodiment. [Figure 8] FIG. 11 is a cross-sectional view showing an electrostatic spraying device according to a seventh embodiment. [Figure 9] FIG. 13 is a cross-sectional view showing an electrostatic spraying device according to an eighth embodiment. [Figure 10] FIG. 13 is a cross-sectional view showing an electrostatic spraying device according to a ninth embodiment. [Figure 11] FIG. 13 is a diagram illustrating a modified example of the fifth embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0027] Each embodiment will be described below with reference to the drawings.

[0028] First Embodiment Fig. 1 shows a schematic diagram of a spraying system S including an electrostatic spraying device 1a according to a first embodiment. Fig. 2 shows a cross-sectional view of the electrostatic spraying device 1a. The spraying system S includes the electrostatic spraying device 1a and a power supply 50.

[0029] In the spray system S, the electrostatic spraying device 1a is connected to one electrode of the power source 50. The opposite electrode 60 is connected to the other electrode opposite to the one electrode of the power source 50. In this embodiment, the electrostatic spraying device 1a is connected to the negative electrode of the power source 50. The opposite electrode part 60 is connected to the positive electrode of the power source 50. The electrostatic spraying device 1a and the opposite electrode part 60 are separated by a space.

[0030] The power supply 50 is a DC power supply. However, the power supply 50 may also be a device including an AC power supply and an AC-DC converter. When a voltage is applied from the power supply 50, a potential difference occurs between the electrostatic spraying device 1a and the opposite electrode portion 60. The electrostatic spraying device 1a is supplied with liquid as described below. The liquid supplied to the electrostatic spraying device 1a is charged by the application of voltage from the power supply 50. In this case, the charged liquid moves toward the opposite electrode portion 60 due to the potential difference between the electrostatic spraying device 1a and the opposite electrode portion 60. This allows the electrostatic spraying device 1a to spray the liquid onto the opposite electrode portion 60. The opposite electrode portion 60 may be an object to which the liquid is to be sprayed. Furthermore, the opposite electrode portion 60 may be a member that holds an object to which the liquid is to be sprayed.

[0031] An earth line 70 is connected to the line between the power supply 50 and the opposite polarity part 60. As a result, the opposite polarity part 60 is grounded via the earth line 70. However, the earth line 70 may be omitted.

[0032] Typical methods of the electrostatic spraying device 1a include electrospraying, electrospinning, etc. The method of such an electrostatic spraying device 1a is not particularly limited.

[0033] As shown in FIG. 2, the electrostatic spraying device 1a includes a flow path forming portion 10 having a liquid flow path 11, and at least two electrodes (20, 30) at least a portion of which is located within or faces the flow path 11 and is arranged at a distance from each other.

[0034] The flow path forming section 10 is formed from an insulating material. One end 11a and the opposite end 11b of the flow path 11 both open from the flow path forming section 10. One end 11a of the flow path 11 is connected to a liquid supply section (not shown). The flow path forming section 10 receives liquid from the liquid supply section into the flow path 11 from one end 11a of the flow path 11. The flow path forming section 10 also causes the liquid in the flow path 11 to flow out from the other end 11b of the flow path 11.

[0035] In this embodiment, the flow path 11 is formed in a crank shape. Specifically, the flow path 11 includes a first portion 11x having one end 11a of the flow path 11, a second portion 11y bending from the first portion 11x, and a third portion 11z bending from the second portion 11y and having the other end 11b of the flow path 11. As an example, the first portion 11x and the third portion 11z extend parallel to each other. The second portion 11y extends in a direction perpendicular to the first portion 11x and the third portion 11z. However, the shape of the flow path 11 is not particularly limited. The liquid may be, for example, paint. However, the type of liquid is not particularly limited.

[0036] In this embodiment, the flow path forming section 10 includes a main body portion 13 having a main flow path portion 12 that constitutes a part of the flow path 11, and a nozzle 14 provided in the main body portion 13. The nozzle 14 receives the liquid from the main flow path portion 12. The upstream end of the main flow path portion 12 forms one end 11a of the flow path 11. The tip of the nozzle 14 forms the other end 11b of the flow path 11. In this embodiment, the flow path 11 is formed by the main flow path portion 12 and a tip flow path portion 14a formed by the inner circumferential surface of the nozzle 14.

[0037] In this embodiment, the nozzle 14 is separate from the main body portion 13. The main flow path portion 12 is formed by a through hole formed in the main body portion 13. The nozzle 14 is fitted into the through hole from the end of the through hole that forms the main flow path portion 12 opposite to the end that forms one end 11a of the flow path 11. However, the manner in which the nozzle 14 is installed in the main body portion 13 is not particularly limited. The nozzle 14 may also be formed integrally with the main body portion 13. In this embodiment, the nozzle 14 is formed from an insulating material. However, the nozzle 14 may also be formed from a conductive material.

[0038] In this embodiment, the electrostatic spraying device 1a includes at least two electrodes (20, 30), namely, a connection electrode 20 and a relay electrode 30. The connection electrode 20 and the relay electrode 30 are made of a conductive material. The connection electrode 20 and the relay electrode 30 may be made of a metal. The connection electrode 20 and the relay electrode 30 may be made of a conductive synthetic resin. Conductivity is the property of conducting electricity. As an example, the connection electrode 20 and the relay electrode 30 are made of a conductive material such as 10 5 It may have a volume resistivity of Ω·cm or less.

[0039] In this embodiment, the connection electrode 20 and the relay electrode 30 are each an elongated member having a longitudinal direction. More specifically, the connection electrode 20 and the relay electrode 30 are rod-shaped.

[0040] As described above, the flow path 11 of the flow path forming section 10 is crank-shaped and includes a first portion 11x, a second portion 11y bending from the first portion 11x, and a third portion 11z bending from the second portion 11y. A through-hole 15 is formed in the flow path forming section 10, penetrating the flow path 11 from the second portion 11y to the outside. A connection electrode 20 is passed through the through-hole 15. One end of the connection electrode 20 is located outside the flow path forming section 10. The other end of the connection electrode 20, opposite to the one end, is located inside the flow path 11. More specifically, the other end of the connection electrode 20 is located inside the third portion 11z. The connection electrode 20 is located across from the second portion 11y to the third portion 11z.

[0041] The connection electrode 20 is held on the inner circumferential surface of the through hole 15. A groove is provided on the inner circumferential surface of the through hole 15. A seal member 16 such as an O-ring is provided in this groove. The seal member 16 is in close contact with the outer circumferential surface of the connection electrode 20. This ensures liquid-tightness between the connection electrode 20 and the flow path forming portion 10.

[0042] The through hole 15 is formed in a surface of the second portion 11y facing the other end 11b of the flow channel 11. In this embodiment, the through hole 15 is positioned coaxially with the opening that is the other end 11b of the flow channel 11. The third portion 11z extends linearly. As a result, the connection electrode 20 extends parallel to the central axis of the third portion 11z of the flow channel 11. Specifically, the connection electrode 20 extends coaxially with the third portion 11z within the third portion 11z. However, the through hole 15 does not have to be coaxial with the other end 11b of the flow channel 11. Furthermore, the connection electrode 20 does not have to extend parallel to the central axis of the third portion 11z of the flow channel 11. Furthermore, the connection electrode 20 does not have to extend coaxially with the third portion 11z within the third portion 11z.

[0043] A knob 21 is provided on the portion of the connection electrode 20 that extends outward from the through hole 15. The knob 21 is made of an insulating material. Insulation is the property of not conducting electricity. For example, the knob 21 is made of an insulating material such as 10 12 The knob 21 may have a volume resistivity of Ω·cm or more. The knob 21 has a through-hole 21a through which the connection electrode 20 passes. The knob 21 is integrated with the connection electrode 20 when the connection electrode 20 passes through the through-hole 21a. The connection electrode 20 extends from the through-hole 21a of the knob 21. A portion of the connection electrode 20 extending from the knob 21, including one end thereof, is connected to a power cable 52 as shown in FIG. 1 . The power cable 52 includes a cable 51 extending from the power source 50 and a connector 51a provided on the cable and detachably connected to the flow path forming unit 10. In other words, the connection electrode 20 is an electrode that is electrically connected to the power source 50.

[0044] The knob 21 is detachably held in a holding hole 17 formed in the flow path forming section 10. More specifically, a male thread is formed on the outer peripheral surface of the knob 21. A female thread is formed on the inner peripheral surface of the holding hole 17. The integral assembly of the connection electrode 20 and the knob 21 is provided in the flow path forming section 10 so that the connection electrode 20 passes through the through hole 21a and the knob 21 is screwed into the holding hole 17. This allows the position of the connection electrode 20 in the flow path 11 to be adjusted by rotating the knob 21. Note that the knob 21 does not necessarily have to be provided.

[0045] 1 and 2, the connection electrode 20 is configured by connecting two rod-shaped members. The configuration of such a connection electrode 20 is not particularly limited. The connection electrode 20 may be configured by a single member. The connection electrode 20 may also be configured by connecting three or more members.

[0046] The relay electrode 30 is located in a third portion 11z of the flow channel 11. The relay electrode 30 is spaced apart from the connection electrode 20. Specifically, the relay electrode 30 is spaced apart from the connection electrode 20 in the direction in which the liquid flows in the flow channel 11. In other words, the relay electrode 30 is located downstream of the connection electrode 20 in the direction in which the liquid flows in the flow channel 11.

[0047] The entire relay electrode 30 is located within the flow path 11. In this embodiment, the entire relay electrode 30 is located within the third portion 11z of the flow path 11. The relay electrode 30 is located within the third portion 11z along the direction of liquid flow. More specifically, the rod-shaped relay electrode 30 is located coaxially with the third portion 11z. The downstream end of the relay electrode 30 is located inside the other end 11b of the flow path 11. However, the downstream end of the relay electrode 30 may be aligned with the other end 11b of the flow path 11. In other words, the position of the downstream end of the relay electrode 30 and the position of the other end 11b of the flow path 11 may be aligned with each other in the direction of liquid flow in the third portion 11z.

[0048] In this embodiment, adjacent connection electrodes 20 and relay electrodes 30 are connected by a linking member 40. The linking member 40 has insulating properties. The insulating material forming the linking member 40 may be, for example, synthetic resin, ceramics, or the like.

[0049] The connecting member 40 is a rod-shaped member. The connecting member 40 is arranged within the third portion 11z along the direction of liquid flow. More specifically, the rod-shaped relay electrode 30 is arranged coaxially with the third portion 11z. A hole is provided at the upstream end of the connecting member 40 to receive the downstream end of the connection electrode 20. A hole is provided at the upstream end of the relay electrode 30 to receive the downstream end of the connecting member 40. By inserting the downstream end of the connection electrode 20 into the hole at the upstream end of the connecting member 40 and inserting the downstream end of the connecting member 40 into the hole at the upstream end of the relay electrode 30, the connection electrode 20 and the relay electrode 30 are connected by the connecting member 40.

[0050] The connection electrode 20, relay electrode 30, and linking member 40 form a rod-like body that extends linearly. The portion of the connection electrode 20 located within the flow path 11 and the portion where the linking member 40 and relay electrode 30 are continuous have a constant outline in a cross-sectional view perpendicular to the direction of liquid flow. This, for example, reduces pressure loss in the liquid. Furthermore, the integrated body of the connection electrode 20, relay electrode 30, and linking member 40 is detachable from the flow path forming portion 10. That is, in this embodiment, both the connection electrode 20 and the relay electrode 30 are detachably provided on the flow path forming portion 10.

[0051] The manner in which the connection electrode 20, the relay electrode 30, and the linking member 40 are connected is not particularly limited. Also, the linking member 40 may not be provided. In this case, in this embodiment, it is desirable to provide a structure for maintaining the posture of the relay electrode 30, for example, in the flow path 11.

[0052] Next, the spraying operation of the spray system S will be described.

[0053] When spraying, the electrostatic spraying device 1a is first connected to one electrode of the power source 50. The opposite electrode 60 is connected to the other electrode opposite to the one electrode of the power source 50. In this state, a voltage is applied from the power source 50, causing a potential difference between the electrostatic spraying device 1a and the opposite electrode 60.

[0054] Simultaneously with, before, or after the application of the voltage, the electrostatic spraying device 1a is supplied with a liquid through the flow path 11. Here, the liquid supplied to the electrostatic spraying device 1a is charged by the application of the voltage from the power supply 50. In this case, the charged liquid moves toward the opposite polarity portion 60 in accordance with the potential difference between the electrostatic spraying device 1a and the opposite polarity portion 60. As a result, the electrostatic spraying device 1a sprays the liquid toward the opposite polarity portion 60.

[0055] In the electrostatic spraying device 1a, a voltage is applied from one of at least two electrodes (the connection electrode 20). Here, the at least two electrodes (the connection electrode 20 and the relay electrode 30) are spaced apart from each other in the flow path 11. As a result, in this embodiment, the occupancy rate of the electrodes in the flow path 11 is reduced compared to, for example, a configuration in which the electrodes span the entire flow path. As a result, the occurrence of discharge is suppressed. Furthermore, within the flow path 11, current may flow between the electrodes (the connection electrode 20 and the relay electrode 30) and current may flow through the fluid between adjacent electrodes (the connection electrode 20 and the relay electrode 30). As a result, the current flow state in the electrostatic spraying device 1a is more stable than in a configuration in which current is flowed through the liquid throughout the entire flow path 11. As a result, the charged state of the liquid is stabilized. Therefore, it is possible to achieve both suppression of discharge and stabilization of the charged state.

[0056] As described above, the electrostatic spraying device 1a according to the first embodiment includes a flow path forming portion 10 having a liquid flow path 11, and at least two electrodes, namely, a connecting electrode 20 and a relay electrode 30, which are arranged apart from each other and at least a portion of which is located within or faces the flow path 11. This electrostatic spraying device 1a can both suppress discharge and stabilize the charged state.

[0057] In this embodiment, the connection electrode 20 and the relay electrode 30 are separated in the direction in which the liquid flows. In this case, a voltage is applied along the direction in which the liquid flows in the flow channel 11. This can stabilize the charged state at the downstream end (other end 11b) of the flow channel 11.

[0058] Moreover, the entire relay electrode 30 is located inside the flow path 11. In this case, compared to when a part of the relay electrode 30 is exposed to the outside of the flow path 11 from the other end 11b of the flow path 11, the risk of discharge can be more effectively reduced and the stability of atomization can be improved.

[0059] In the illustrated example, the connection electrode 20 is connected to a connector 51a provided on a cable 51 extending from the power source 50. In this case, voltage can be easily applied by connecting the connector 51a to the connection electrode 20. The power source 50 may also be built into the electrostatic spraying device 1a. In this case, the electrostatic spraying device 1a may be provided with a high-voltage generating circuit to boost the voltage.

[0060] Adjacent connection electrodes 20 and relay electrodes 30 are connected by an insulating linking member 40. In this case, the connection electrodes 20, relay electrodes 30, and linking member 40 can be handled as a single integrated member, which simplifies assembly and maintenance work.

[0061] <Second embodiment> Next, a second embodiment will be described with reference to Fig. 3. Among the components in this embodiment, the same components as those in the first embodiment will be assigned the same reference numerals, and duplicated descriptions will be omitted.

[0062] FIG. 3 shows an electrostatic spraying device 1b according to a second embodiment. In the second embodiment, the configuration of the relay electrode 30 differs from that of the first embodiment. As shown in FIG. 3, the relay electrode 30 is formed from a wire. Specifically, the relay electrode 30 includes an attachment portion 31 that is held directly or indirectly by the flow path forming portion 10, and an electrode main body portion 32 that extends from the attachment portion 31 along the flow path 11. The attachment portion 31 is formed from a portion of the wire that is formed into a spiral shape. The electrode main body portion 32 is formed from a portion of the wire that extends linearly. The wire may have a diameter of 3 mm or less.

[0063] In this embodiment, the attachment portion 31 of the relay electrode 30 is held by the coupling member 40. The coupling member 40 is connected to the connection electrode 20. Then, as in the first embodiment, the connection electrode 20 is passed through the through hole 15 of the flow path forming portion 10. Then, the connection electrode 20 is held by the flow path forming portion 10 via the through hole 15. In this way, the relay electrode 30 is indirectly held by the flow path forming portion 10 via the coupling member 40 and the connection electrode 20.

[0064] The configuration of the connecting member 40 differs from that of the first embodiment. Specifically, the connecting member 40 includes a base 41 and a tubular portion 42 attached to the base 41. The base 41 extends longitudinally along the direction in which the liquid flows in the flow path 11. The base 41 is rod-shaped. One end of the base 41 is connected to the connection electrode 20. The tubular portion 42 is attached to the other end of the base 41 opposite to the one end.

[0065] The inner circumferential surface of the cylindrical portion 42 has a first hole 43a for receiving the mounting portion 31 and a second hole 43b having a smaller diameter than the first hole 43a for passing the electrode main body 32. When the mounting portion 31 of the relay electrode 30 is held in the connecting member 40, the electrode main body 32 is first passed through the second hole 43b via the first hole 43a. Next, the mounting portion 31 of the relay electrode 30 is inserted into the first hole 43a. The mounting portion 31 is then brought into contact with or close to the step surface between the first hole 43a and the second hole 43b. Here, a portion of the inner circumferential surface of the first hole 43a that is not covered by the mounting portion 31 is formed on the side opposite to the second hole 43b. The portion of the inner circumferential surface of the first hole 43a that is not covered by the mounting portion 31 is then attached to the outer circumferential surface of the base 41. As a result, the mounting portion 31 of the relay electrode 30 is sandwiched between the base portion 41 and the cylindrical portion 42. In this manner, the mounting portion 31 of the relay electrode 30 is held by the connecting member 40. Then, the relay electrode 30 and the connecting member 40 are connected to each other.

[0066] In this embodiment, base 41 includes a rod-shaped large diameter portion 41a and a small diameter portion 41b having a smaller diameter than large diameter portion 41a. The portion of the inner circumferential surface of first hole 43a that is not covered by mounting portion 31 is attached to the outer circumferential surface of small diameter portion 41b. The portion of the inner circumferential surface of first hole 43a that is not covered by mounting portion 31 and small diameter portion 41b may be attached by press fitting, snap fitting, or the like.

[0067] The second embodiment described above also achieves both suppression of discharge and stabilization of the charged state. In this embodiment, the relay electrode 30 is formed from a wire. In this case, the relay electrode 30 can be easily formed. In this embodiment, the attachment portion 31 is formed from a portion of the wire formed into a spiral shape. This makes it extremely easy to form the attachment portion 31. In particular, when the diameter of the wire is 3 mm or less, the spiral attachment portion 31 can be easily formed.

[0068] <Third embodiment> Next, a third embodiment will be described with reference to Fig. 4. Among the components in this embodiment, the same components as those in the first and second embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0069] FIG. 4 shows an electrostatic spraying device 1c according to a third embodiment. In the third embodiment, the configuration of the flow path forming section 10 differs from that of the first embodiment. As shown in FIG. 4, the flow path forming section 10 includes a first part 101, a second part 102, and a third part 103. The first part 101 has a first flow path section 101a that forms part of the flow path 11. The second part 102 has a second flow path section 102a that forms part of the flow path 11. The third part 103 has a third flow path section 103a that forms part of the flow path 11. The first part 101, the second part 102, and the third part 103 are insulating.

[0070] The second component 102 connects the first component 101 and the third component 103. The second component 102 connects the second flow path portion 102a to the first flow path portion 101a and the third flow path portion 103a. More specifically, the second component 102 is connected to the first component 101 via a first connector portion 104. The second component 102 is connected to the third component 103 via a second connector portion 105.

[0071] The first flow path portion 101a in the first component 101 is formed by a through-hole formed in the first component 101. The first flow path portion 101a has one end 11a of a flow path 11 that receives a liquid. The first component 101 is provided with a connection electrode 20. The manner in which the connection electrode 20 is installed on the first component 101 is the same as in the first embodiment.

[0072] The second part 102 is tubular. The second part 102 forms a second flow path portion 102a with its inner circumferential surface. One end of the second part 102 is connected to the first connector portion 104. The other end opposite to the one end of the second part 102 is connected to the second connector portion 105. In this embodiment, the second part 102 is formed in a crank shape. However, the shape of the second part 102 is not particularly limited. The second part 102 may be formed in a linear shape, an L-shape, or the like. The second part 102 may be flexible. The second part 102 may be bendable. The second part 102 may be made of rubber.

[0073] The first connector portion 104 is cylindrical. A portion of the second component 102 including one end is inserted into the first connector portion 104. This connects the second component 102 and the first connector portion 104. The first connector portion 104 is inserted into the inside of a through-hole that forms the first flow path portion 101a in the first component 101. This connects the first connector portion 104 to the first component 101. The first connector portion 104 and the first component 101 may be connected by press-fitting. The first connector portion 104 and the first component 101 may be connected by screwing.

[0074] In this embodiment, the relay electrode 30 is held between the second component 102 and the first connector portion 104. The relay electrode 30 has the same configuration as the second embodiment. A step portion 104S that protrudes radially inward is formed on the inner circumferential surface of the first connector portion 104. The mounting portion 31 of the relay electrode 30 is sandwiched between the step portion 104S and one end of the second component 102. This allows the relay electrode 30 to be held between the second component 102 and the first connector portion 104. The electrode main body portion 32 extends inside the second component 102 along the longitudinal direction of the second component 102.

[0075] The second connector portion 105 is cylindrical. A portion of the second component 102 including the other end thereof is inserted into the second connector portion 105. This connects the second component 102 and the second connector portion 105. A step portion 105S that protrudes radially inward is also formed on the inner circumferential surface of the second connector portion 105. The other end of the second component 102 is in contact with or close to the step portion 105S of the second connector portion 105.

[0076] The third flow path portion 103a in the third part 103 is formed by a through hole formed in the third part 103. The third flow path portion 103a has one end 11a of the flow path 11 that receives liquid and the other end 11b opposite the other end 11a. The second connector part 105 is inserted into the through hole that forms the third flow path portion 103a in the third part 103. In this way, the second connector part 105 is connected to the third part 103. The second connector part 105 and the third part 103 may be connected by press-fitting. The second connector part 105 and the third part 103 may be connected by screwing.

[0077] More specifically, the third component 103 includes a main body portion 103M that connects to the second component 102, and a nozzle 14 provided in the main body portion 103M. The nozzle 14 may be made of an insulating material. The nozzle 14 may also be made of a conductive material.

[0078] Furthermore, in this embodiment, no linking member 40 is provided. The connection electrode 20 and the relay electrode 30 are separated by a part of the flow path 11. Therefore, when a voltage is applied from the connection electrode 20, current may flow through the connection electrode 20, current may flow through the liquid between the connection electrode 20 and the relay electrode 30, current may flow through the relay electrode 30, and current may flow through the liquid downstream of the relay electrode 30.

[0079] The third embodiment described above also achieves both suppression of discharge and stabilization of the charged state. In this embodiment, the flow path forming unit 10 includes a first component 101 having a first flow path portion 101a that constitutes a part of the flow path 11, a second component 102 having a second flow path portion 102a that constitutes a part of the flow path 11, and a third component 103 having a third flow path portion 103a that constitutes a part of the flow path 11. The second component 102 is tubular and forms the second flow path portion 102a on its inner circumferential surface. The second component 102 connects the first component 101 and the third component 103, and connects the second flow path portion 102a to the first flow path portion 101a and the third flow path portion 103a. This configuration facilitates coating operations, for example, when the distance between the electrostatic spraying device 1c and the object to be sprayed is relatively long.

[0080] <Fourth embodiment> Next, a fourth embodiment will be described with reference to Fig. 5. Among the components in this embodiment, the same components as those in the first to third embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0081] FIG. 5 shows an electrostatic spraying device 1d according to a fourth embodiment. In the fourth embodiment, the position of the relay electrode 30 differs from that of the third embodiment. Specifically, the mounting portion 31 of the relay electrode 30 is held between the second component 102 and the second connector portion 105. On the other hand, the relay electrode 30 is not held between the first connector portion 104 and the second component 102. The other configurations are the same as those of the third embodiment.

[0082] <Fifth embodiment> Next, a fifth embodiment will be described with reference to Fig. 6. Among the components in this embodiment, the same components as those in the first to fourth embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0083] 6 shows an electrostatic spraying device 1e according to a fifth embodiment. The electrostatic spraying device 1e includes a first component 101, a plurality of (two in this example) second components 102, and a plurality of (two in this example) third components 103. The two second components 102 are connected to the first component 101 via a single first connector 104r. The two second components 102 are respectively connected to corresponding third components 103. The second components 102 are connected to the third components 103 via second connectors 105.

[0084] The first connector portion 104r has a first port portion 141 having a receiving flow path 141a through which liquid flows in from the first flow path portion 101a of the first component 101, a first branch port portion 142 having a first branch flow path 142a connected to the downstream end of the receiving flow path 141a, and a second branch port portion 143 having a second branch flow path 143a connected to the downstream end of the receiving flow path 141a. The first branch flow path 142a and the second branch flow path 143a are bifurcated from the downstream end of the receiving flow path 141a.

[0085] The first port portion 141 is inserted into the inside of a through-hole that forms the first flow path portion 101a in the first component 101. This connects the first port portion 141 to the first component 101. One of the two second components 102 is inserted into the inside of the first branch flow path 142a from the downstream end of the first branch flow path 142a in the first branch port portion 142. The other of the two second components 102, which is different from the one of the two, is inserted into the inside of the second branch flow path 143a from the downstream end of the second branch flow path 143a in the second branch port portion 143. The function of the second component 102 is the same as in the third embodiment. However, the shape of the second component 102 in this embodiment is different from that in the third embodiment.

[0086] The electrostatic spraying device 1e also includes a plurality of (two in this example) relay electrodes 30. The relay electrodes 30 have the same configuration as in the second embodiment. The mounting portion 31 of one of the two relay electrodes 30 is held between the first branch port portion 142 of the first connector portion 104r and the second component 102. The mounting portion 31 of the other relay electrode 30, which is different from one of the two relay electrodes 30, is held between the second branch port portion 143 of the first connector portion 104r and the second component 102. It is assumed that the first flow path portion 101a of the first component 101 in the flow path forming unit 10, the receiving flow path 141a and the first branch flow path 142a of the first connector portion 104r, a flow path portion of one of the two second components 102 inserted into the first branch flow path 142a, and a flow path portion of the third component 103 connected to one of the two second components 102 form the "flow path 11" of the flow path forming unit 10. In this case, the second branch flow path 143a in the first connector portion 104r, a flow path portion in the other of the two second components 102 inserted into the second branch flow path 143a, and a flow path portion in the third component 103 connected to the other of the two second components 102 form an additional flow path connected between one end and the other end of the flow path 11. The relay electrode 30 arranged in this additional flow path corresponds to an additional electrode at least a portion of which is located in or faces the additional flow path.

[0087] The fifth embodiment described above also makes it possible to suppress discharge and stabilize the charged state at the same time. Furthermore, in this embodiment, liquid can be sprayed from two third components 103. This improves the efficiency of the spraying operation. The second components 102 may have different lengths. In this case, the length of the relay electrode 30 in each second component 102 may be adjusted to match the different lengths of the second components 102. Specifically, the length of the relay electrode 30 in the longer second component 102 may be longer than the length of the relay electrode 30 in the shorter second component 102. In this case, the charge of the third component 103 is stabilized, enabling good spraying.

[0088] Sixth Embodiment Next, a sixth embodiment will be described with reference to Fig. 7. Among the components in this embodiment, the same components as those in the first to fifth embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0089] 7 shows an electrostatic spraying device 1f according to a sixth embodiment. In the electrostatic spraying device 1f, a branch flow path 200 is formed, which branches off from the flow path 11 of the flow path forming section 10 in the second embodiment. The flow path forming section 10 is provided with a second component 102 having a shape similar to that of the fifth embodiment, which is fluidly connected to the branch flow path 200. A third component 103 similar to that of the fifth embodiment is connected to the second component 102. That is, the flow path forming section 10 includes a main body portion in which the flow path 11 is provided, the second component 102, and the third component 103.

[0090] An attachment tube portion 201 is formed around the open end of the branch flow path 200 on the outer peripheral surface of the flow path forming portion 10. The second part 102 is connected to the attachment tube portion 201 via a first connector portion 104 similar to those in the third to fifth embodiments. The electrostatic spraying device 1f further includes a relay electrode 30 in addition to the relay electrode 30 located in the flow path 11. The other relay electrode 30 has a configuration similar to that of the second embodiment. However, the attachment portion 31 of the other relay electrode 30 is held between the first connector portion 104 and the second part 102. The electrode main body portion 32 of the other relay electrode 30 is located in the second part 102. In this embodiment, the branch flow path 200, a flow path portion in the second part 102, and a flow path portion in the third part 103 form an additional flow path connected between one end and the other end of the flow path 11. The relay electrode 30 located in this additional flow path corresponds to an additional electrode at least a portion of which is located in or faces the additional flow path.

[0091] According to the sixth embodiment described above, the same effects as those of the fifth embodiment can be obtained.

[0092] Seventh Embodiment Next, a seventh embodiment will be described with reference to Fig. 8. Among the components in this embodiment, the same components as those in the first to sixth embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0093] 8 shows an electrostatic spraying device 1g according to the seventh embodiment, a power supply 50 connected to the electrostatic spraying device 1g, etc. The electrostatic spraying device 1g is configured by adding an equipotential line adjusting electrode 80 to the electrostatic spraying device 1a according to the first embodiment.

[0094] In the seventh embodiment, the nozzle 14 in the flow path forming part 10 is formed from a conductive member. An equipotential line adjusting electrode 80 is connected to the nozzle 14. The potential adjusting electrode 80 may be connected to a power supply different from the power supply 50, for example. The equipotential line adjusting electrode 80 is provided so as not to extend beyond the tip of the nozzle 14.

[0095] In the seventh embodiment, when a voltage is applied from the power supply 50 to the connection electrode 20 and then to the equipotential line adjustment electrode 80, the potential difference between the connection electrode 20 and the equipotential line adjustment electrode 80 can be suppressed. In this case, the state of the electric field formed between the electrostatic spraying device 1g and the opposite electrode part 60 can be made suitable for spraying. This allows for good spraying.

[0096] <Eighth embodiment> Next, an eighth embodiment will be described with reference to Fig. 9. Among the components in this embodiment, the same components as those in the first to seventh embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0097] FIG. 9 shows an electrostatic spraying device 1h according to an eighth embodiment. The electrostatic spraying device 1h includes a power cable 52. The power cable 52 is integrated with the connection electrode 20. More specifically, a connector 51a and the connection electrode 20 are integrated. The connector 51a is detachably attached to the flow path forming portion 10. FIG. 9(A) shows a state in which the connector 51a has been removed from the flow path forming portion 10. From this state, the connector 51a is attached to the flow path forming portion 10 as shown in FIG. 9(B). In this state, the connection electrode 20 integrated with the connector 51a is partially positioned within the flow path 11 of the flow path forming portion 10. The connection electrode 20 and the relay electrode 30 are separated from each other.

[0098] The eighth embodiment described above also makes it possible to suppress discharge and stabilize the charged state at the same time. Note that the connection electrode 20 may be integrated with the power supply instead of being integrated with the power cable 52. Furthermore, the connection electrode 20 may be integrated with the power supply and the high-voltage generating circuit.

[0099] <Ninth embodiment> Next, a ninth embodiment will be described with reference to Fig. 10. Among the components in this embodiment, the same components as those in the first to eighth embodiments are designated by the same reference numerals, and duplicated descriptions will be omitted.

[0100] FIG. 10 shows an electrostatic spraying device 1i according to a ninth embodiment. In this embodiment, the configuration of the relay electrode 30 differs from that of the first embodiment. The relay electrode 30 in this embodiment is formed from a tubular member. The relay electrode 30 is provided on the outer peripheral surface of a connecting member 40. The connecting member 40 protrudes downstream from the relay electrode 30. The tip portion of the connecting member 40 protruding from the relay electrode 30 reaches the tip of the nozzle 14. The relay electrode 30 may be formed from a member formed by rolling a thin plate. In this case, the relay electrode 30 does not necessarily have to be tubular. Specifically, the cross-sectional shape of the relay electrode 30 in a direction perpendicular to the longitudinal direction may be C-shaped, arc-shaped, or the like. The connection mode between the relay electrode 30 and the connecting member 40 is not particularly limited.

[0101] Although the embodiments of the present disclosure have been described above, various modifications may be made to the above-described embodiments. Such modifications may also fall within the technical scope of the present disclosure. FIG. 11 illustrates a modification of the fifth embodiment illustrated in FIG. 6. In the modification illustrated in FIG. 11, a valve 90 is provided in each of two second components 102 that form a liquid flow path. The valve 90 can switch between allowing and blocking fluid flow by opening and closing. Closing the valve 90 prevents liquid from leaking from the nozzle (14 in FIG. 1, etc.). In the modification illustrated in FIG. 11, multiple valves 90 are provided, one for each nozzle. The multiple nozzles may be controlled individually or synchronously. In the modification illustrated in FIG. 11, the valve 90 is provided in the pipe-shaped second component 102, but the installation position is not particularly limited. For example, the valve 90 may be integrated into the nozzle portion of the third component 103 or into the first connector portion 104r illustrated in FIG. 11. These aspects can be expected to reduce the number of components and make the device more compact. It should be noted that the valve 90 is also beneficial when applied to other embodiments. [Explanation of symbols]

[0102] S...Spray system 1a, 1b, 1c, 1d, 1e, 1f, 1g, 1h, 1i...Electrostatic spraying device 10...flow path forming section 101...First part 101a...first flow path section 102...Second part 102a...second flow path section 103...Third part 103a...Third flow path section 103M…Body part 104, 104r...First connector part 141...Upstream port section 141a...receiving flow path 142...First branch port 142a...first branch flow path 143...Second branch port 143a...second branch flow path 105...Second connector part 104S, 105S...Stepped section 11...Flow path 11a…one end 11b...other end 11x…1st part 11y…Second part 11z…3rd part 12...Main flow section 13…Body part 14a... Tip flow path section 15...Through hole 16...Sealing member 17...Retaining hole 20...Connection electrode 21...Knob 30...Relay electrode 31...Mounting part 32...Electrode body part 40...Connecting member 41...Base 41a...Large diameter part 41b…Small diameter part 42...Cylindrical part 43...Through hole 43a...First hole 43b…Second hole 50...Power supply 51...Cable 51a...Connector 52...Power cable 60...Heterogenous area 70...Earth line 80...Equipotential line adjustment electrode

Claims

1. a flow path forming portion having a flow path for a liquid, receiving the liquid from one end of the flow path and discharging the liquid from the other end opposite to the one end of the flow path; and at least two electrodes spaced apart from each other, at least a portion of which is located within or faces the flow path.

2. the flow path forming portion includes an additional flow path connected between the one end and the other end of the flow path, the additional flow path receiving the liquid from the flow path and discharging the liquid from a downstream end thereof; The electrostatic spraying device of claim 1 , further comprising an additional electrode at least a portion of which is located within or faces the additional flow path.

3. The electrostatic spraying device of claim 1 , wherein the at least two electrodes are spaced apart in a direction in which the liquid flows.

4. The electrostatic spray device of claim 1 , wherein the at least two electrodes include at least one electrode located entirely within the flow path.

5. The electrostatic spraying device according to claim 1 , wherein the at least two electrodes include a connection electrode electrically connected to a power source.

6. The electrostatic spraying device according to claim 5 , wherein the electrode different from the connection electrode among the at least two electrodes is formed from a wire material.

7. The electrostatic spraying device according to claim 5 , wherein the electrode different from the connection electrode among the at least two electrodes is formed from a tubular member or a member formed by rolling a thin plate.

8. The electrostatic spraying device according to claim 1 , wherein at least one of the at least two electrodes is detachably provided in the flow path forming portion.

9. 2. The electrostatic spraying device of claim 1, wherein the at least two electrodes include at least one electrode including an attachment portion that is held directly or indirectly to the flow path forming portion and an electrode main body portion that extends from the attachment portion along the flow path.

10. the electrode including the mounting portion and the electrode main body portion is formed from a wire material, The electrostatic spraying device according to claim 9 , wherein the attachment portion is formed by forming a part of the wire into a spiral shape.

11. The electrostatic spraying device according to claim 1 , further comprising an insulating connecting member connecting adjacent electrodes of the at least two electrodes.

12. the flow path forming portion includes a first component having a first flow path portion that constitutes a part of the flow path, a second component having a second flow path portion that constitutes a part of the flow path, and a third component having a third flow path portion that constitutes a part of the flow path, the second component is tubular and defines the second flow path portion on its inner circumferential surface; The electrostatic spraying device according to claim 1 , wherein the second component connects the first component and the third component, and connects the second flow path portion to the first flow path portion and the third flow path portion.

13. 2. The electrostatic spraying device of claim 1, wherein the flow path forming portion includes a main body portion having a main flow path portion that forms part of the flow path, and a nozzle provided in the main body portion that receives the liquid from the main flow path portion, and the flow path is formed by the main flow path portion and an inner peripheral portion of the nozzle.

14. a power cable including a cable connected to a power source and a connector provided on the cable and detachably connected to the flow path forming portion; one electrode of the at least two electrodes is integrated into the connector; The electrostatic spraying device according to claim 1 , wherein when the connector is connected to the flow path forming portion, a portion of the electrode integrated into the connector is positioned within or faces the flow path.

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