WO2016015600A1

WO2016015600A1 - Electrostatic powder spray coating device and spray coating method

Info

Publication number: WO2016015600A1
Application number: PCT/CN2015/084994
Authority: WO
Inventors: 王冬洋; 贺小明
Original assignee: 深圳市大富科技股份有限公司
Priority date: 2014-07-31
Filing date: 2015-07-24
Publication date: 2016-02-04
Also published as: CN104162492B; CN104162492A

Abstract

Provided are an electrostatic powder spray coating device and a spray coating method therefor. The device comprises a jet stream generating element (21), an electric field generating element (22) and an electric field shaping element (23), wherein the jet stream generating element (21) is used to produce a jet stream carrying electrically charged powder particles, the electric field generating element (22) is used to produce an electrostatic force field for guiding the electrically charged powder particles between the electric field generating element (22) and an element (30) to be spray-coated, and the electric field shaping element (23) is used to shape the electrostatic force field so as to reduce the Faraday cage electrostatic shielding effect of the electrostatic force around a recessed region (31) of the element (30) to be spray-coated. The spray coating device can improve the powdering depth in the recessed region (31).

Description

Electrostatic powder spraying device and spraying method thereof

The present application claims priority to Chinese Patent Application No. 201410373703.9, the entire disclosure of which is hereby incorporated by reference. In this application.

[Technical Field]

The invention relates to the field of high-voltage electrostatic powder spraying technology, in particular to an electrostatic powder spraying device and a spraying method thereof.

【Background technique】

1 is a schematic view of the operation of a prior art high pressure electrostatic spray gun. Referring to FIG. 1, the high-pressure electrostatic spray gun 10 applies high-voltage electricity to the spray gun head 11 for discharging during the dusting operation, and when the spray powder mixed with the high-pressure jet airflow passes through the spray gun head 11, the negative charge is induced. To form charged powder particles and fly to the component 13 to be sprayed, at this time, the component 13 to be sprayed is grounded to form a positive electrode, thereby generating an electrostatic force field between the spray head 11 and the component 13 to be sprayed, and the charged powder particles are adsorbed by the electrostatic force. The surface of the component 13 to be sprayed is then heated to melt-solidify or plasticize the charged powder particles into a coating.

However, when the surface of the member to be painted 13 has a recessed area 131 such as a deep recess or a groove, the prior art high-pressure electrostatic spray gun 10 cannot overcome the electrostatic force of the Faraday around the recessed area 131 when spraying the recessed area 131. The cage electrostatic shielding effect, that is, the power line of the electrostatic force field cannot enter the inside of the recessed area 131, so that the charged powder particles cannot be guided by the electrostatic force to the inside of the recessed area 131, thereby reducing the powder depth in the recessed area 131, and even producing no The problem with the powder.

[Summary of the Invention]

In view of this, the technical problem to be solved by the embodiments of the present invention is to provide an electrostatic powder spraying device and a spraying method thereof, which can solve the problem that the component to be painted is not powdered due to the electrostatic shielding effect of the Faraday cage in the recessed region, and improve the depression. The depth of the powder on the area.

In order to solve the above technical problem, the present invention adopts a technical solution to provide an electrostatic powder spraying device, comprising: a jet stream generating element for generating an jet stream carrying charged powder particles; and a flow guiding element for guiding The jet stream is helically moved about its axis of motion; an electric field generating element for generating a charge between the electric field generating element and the element to be painted An electrostatic force field of the powder particles; an electric field shaping element for shaping the electrostatic force field to reduce the electrostatic shielding effect of the electrostatic force on the Faraday cage around the recessed area of the component to be painted, wherein the electric field shaping element is sleeved on the electric field An insulating kit for generating a periphery of the component, the free end of the insulating sleeve being configured to extend into the interior of the recessed area of the component to be painted, thereby directing the jet stream to the interior of the recessed region and perpendicular to the axis of motion of the jet stream In at least one dimension, the electric field distribution region of the electrostatic force field shaped by the electric field shaping element is smaller than the electric field distribution region of the electrostatic force field not shaped by the electric field shaping element.

Wherein the size of the insulating package in at least one dimension is smaller than the size of the recessed area in the corresponding dimension.

Among them, the insulation kit is in a tubular arrangement.

Wherein the jet stream generating element further comprises a discharge electrode needle for forming charged powder particles, and the discharge electrode needle is disposed inside the insulation kit.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide an electrostatic powder spraying device comprising: a jet stream generating element for generating a jet stream carrying charged powder particles; and an electric field generating element for An electrostatic force field for guiding charged powder particles is generated between the electric field generating element and the component to be painted; an electric field shaping element is used to shape the electrostatic force field to reduce the electrostatic force Faraday around the recessed area of the component to be painted Cage electrostatic shielding effect.

Wherein, the electric field shaping element is an insulation kit that is sleeved around the periphery of the electric field generating element.

Wherein, in at least one dimension perpendicular to the axis of motion of the jet stream, the electric field distribution region of the electrostatic force field shaped by the electric field shaping element is smaller than the electric field distribution region of the electrostatic force field not shaped by the electric field shaping element.

Among them, the insulation kit is in a tubular arrangement.

Wherein the jet stream generating element further comprises a discharge electrode needle for forming charged powder particles, wherein the discharge electrode needle is disposed inside the insulating package.

Wherein, the free end of the insulating sleeve is arranged to protrude into the interior of the recessed area of the component to be painted, thereby guiding the jet stream to the interior of the recessed area.

Wherein, the electrostatic powder spraying device further comprises a flow guiding element, and the flow guiding element is used for guiding the spraying The jet stream moves helically about the axis of motion.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide an electrostatic powder coating method, comprising: generating an electrostatic force field between an electric field generating element and a component to be painted; and using an electric field shaping component to perform an electrostatic force field Forming; using the shaped electrostatic force field to direct the charged powder particles in the jet stream to the recessed area of the component to be painted, wherein the electrostatic force field shaped by the electric field shaping element is generated around the recessed area of the component to be painted The electrostatic shielding effect of the cage is smaller than the electrostatic shielding effect of the Faraday cage generated by the electrostatic force field which is not shaped by the electric field shaping element around the recessed area of the component to be painted.

Wherein, the step of shaping the electrostatic force field by the electric field shaping element comprises: shaping the electrostatic force field by using an insulation kit sleeved around the periphery of the electric field generating element.

Wherein the step of shaping the electrostatic force field by means of an insulating kit sleeved on the periphery of the electric field generating element comprises: an electric field of the electrostatic force field shaped by the electric field shaping element in at least one dimension perpendicular to the axis of motion of the jet stream The distribution area is smaller than the electric field distribution area of the electrostatic force field that is not shaped by the electric field shaping element.

Among them, the insulation kit is in a tubular arrangement.

Wherein, the step of guiding the charged powder particles in the jet stream to the recessed region of the component to be sprayed by the shaped electrostatic force field further comprises: forming the charged powder particles by using the discharge electrode disposed inside the insulating kit.

Wherein, the step of guiding the charged powder particles in the jet stream to the recessed region of the component to be sprayed by using the shaped electrostatic force field comprises: guiding the jet stream to the inside of the recessed region by using the insulating package.

Wherein, the step of guiding the charged powder particles in the jet stream to the recessed region of the component to be sprayed by using the shaped electrostatic force field comprises: using the flow guiding element for guiding the jet stream to spirally move along the axis of motion.

Through the above technical solution, the beneficial effects produced by the embodiments of the present invention are: the electrostatic powder coating device is designed to include an electric field shaping component, and the electrostatic force field generated by the electric field generating component is shaped by the electric field shaping component, so that not only the spray powder can be charged to ensure sufficient The guiding force, and can reduce the electrostatic force field between the electric field shaping element and the component to be painted, thereby reducing the electrostatic force The electrostatic shielding effect of the Faraday cage around the recessed area of the component to be sprayed solves the problem of no powder generated by the electrostatic shielding effect of the Faraday cage around the recessed area, and improves the powder depth of the component to be painted in the recessed area.

[Description of the Drawings]

1 is a schematic view showing the operation of a high-voltage electrostatic powder spray gun of the prior art;

2 is a schematic structural view of an electrostatic powder coating apparatus according to a preferred embodiment of the present invention;

Figure 3 is a schematic cross-sectional view of the flow guiding element of the electrostatic powder coating apparatus shown in Figure 2;

Figure 4 is a schematic illustration of a preferred embodiment of the electrostatic powder coating apparatus of the present invention for curing a coating on an element to be painted;

Figure 5 is a cross-sectional view along the A-A direction of the component to be painted shown in Figure 4;

Figure 6 is a cross-sectional view taken along line B-B of the member to be painted shown in Figure 4;

Figure 7 is a cross-sectional view taken along line C-C of the member to be painted shown in Figure 4;

Figure 8 is a cross-sectional view along the D-D direction of the component to be painted shown in Figure 4;

9-10 are enlarged schematic views of a coating at position 4 using a prior art high pressure electrostatic spray gun;

11-12 are enlarged schematic views of a coating formed by curing a high pressure electrostatic spray gun of the prior art at position 5;

13-14 are enlarged schematic views of a coating formed by curing at a position 14 using a prior art high pressure electrostatic spray gun;

Figure 15 is a flow chart showing an electrostatic powder coating method in accordance with a preferred embodiment of the present invention.

【detailed description】

The technical solutions in the embodiments of the present invention are clearly and completely described in the following with reference to the accompanying drawings in the embodiments of the present invention. It is obvious that the embodiments described below are only a part of the embodiments of the present invention, and not all of them. Example. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

Please refer to Figure 1 again. In the process of high-voltage electrostatic powder spraying, the principle of generating the electrostatic shielding effect of the Faraday cage around the recessed area is as follows:

Since the negative ion is generated when the spray head is discharged, there is a cloud between the spray head and the component to be sprayed, which consists of charged powder particles and negatively charged free ions. The cloud is inevitably between the cloud and the component to be sprayed. A certain electric field is generated, which is commonly referred to as a space charge electric field. Therefore, the electric field adjacent to the surface of the component to be painted is essentially composed of the electric field and space charge electric field generated when high pressure static electricity is applied by the lance tip. The two electric fields together with the aerodynamic force provided by the jet stream direct the charged powder particles to the surface of the component to be painted to effect powdering.

When the surface of the component to be painted has a recessed area such as a deep recess or a groove, the electric power line of the electrostatic force field is concentrated to the place with the lowest electric field resistance, that is, around the recessed area (at the edge), so that the power line cannot enter the inside of the recessed area. .

On the one hand, since the charged powder particles are subjected to electrostatic force and the direction of the electric power line is the direction of the electrostatic force, the electric power line cannot enter the inside of the recessed area, and the charged powder particles enter the inside of the recessed area, which lacks an important driving force.

On the other hand, an increase in the field strength at the edge causes the charged powder particles to adsorb more at the edge, resulting in a marked increase in the thickness of the charged powder particles at the edges of the depressed regions, inevitably producing two negative effects. First, since the charged powder particles are guided by the electrostatic force to the edge of the recessed region, only a small amount of charged powder particles enter the inside of the recessed region. Second, since the free ions generated by the discharge when the nozzle head applies high-voltage static electricity, it is deposited along the power line at the edge of the recessed area, so that the previously deposited charged powder particles are quickly saturated by the excess charge, causing the reverse ionization to be very rapid and intense. .

Since the charged powder particles are collectively guided to the surface of the component to be painted by the aerodynamic force and the electrostatic force of the jet stream, and the higher aerodynamic force easily causes the charged powder particles to rebound by the surface of the component to be sprayed and is not easily deposited, so when spraying There must be a strong enough electric field to provide the electric field force. However, the electrostatic shielding effect of the Faraday cage around the recessed area makes it impossible for the electric field generated by the discharge of the spray head or the space charge electric field formed by the charged powder particles and the free ions to enter the interior of the recessed area, thereby helping the charged powder particles to enter the recessed area. The only internal force is the electric field generated by the "clouds" of charged powder particles and free ions that are transported by the jet stream inside the recessed area.

Based on the above, it can be seen that the configuration of the electrostatic force field and the concentration of the power line at the edge of the recessed area are not the only problems in solving the problem that the recessed area cannot be powdered, because if the recessed area is sprayed for a long time, a certain thickness is deposited at the edge. Other charged strips The electric powder particles can no longer be deposited at the edge, and the only place to go is to enter the interior of the recessed area. However, due to the reverse ionization, if the depth of the recessed region is large or the width is small, the reverse ionization of the edge which develops rapidly will generate positively charged ions, and is forced to pass through the edge of the recessed region to deposit The internal charged powder particles are reduced in charge by these ions, so that the electric field generated by the "clouds" formed by the charged powder particles and free ions pushed by the jet stream into the recessed region cannot generate a sufficiently strong electrostatic force. Overcoming air turbulence and depositing charged powder particles.

Even if the second spraying is used, that is, the second spraying after the first heating and curing, the problem of the powder-free effect caused by the electrostatic shielding effect of the Faraday cage cannot be solved because the free ions generated by the discharge are in the nozzle head and to be sprayed. There is a rapid movement between the components, and the speed of movement is much higher than the speed of the charged powder particles. When the free ions move to the surface of the component to be painted, the charge in the cured coating is rapidly increased. The cured coating has a greater dielectric constant than the uncured coating, ie, has better insulation. Therefore, the charge brought by the free ions to the surface of the component to be painted cannot leak into the ground loop, so that the free ions rapidly increase the charge on the coating, thereby further causing reverse ionization, so that the powdering rate is drastically lowered. In practical applications, the aspect ratio of the recessed area exceeding 5:1 cannot be uniformly powdered.

According to the above principle, in order to enable the recessed area to be powdered, three problems need to be solved: first, avoiding a strong electrostatic force field on the surface of the spray head and the component to be painted during spraying, thereby avoiding the generation of Faraday cage static electricity in the recessed area. Shielding effect; Secondly, it is necessary to make the spray powder capable of carrying high-voltage static electricity. If the spray powder is not loaded with high-voltage negative charge, it will fall under the influence of gravity and will not deposit. Third, the recessed area is difficult to connect with air. The semi-closed cavity that enters can effectively guide the spray powder to the inside of the recessed area.

Accordingly, it is a primary object of the present invention to provide an electrostatic powder coating apparatus and an electrostatic powder coating method based on the apparatus to solve the above three problems.

2 is a schematic view showing the structure of an electrostatic powder coating apparatus according to an embodiment of the present invention. Referring to FIG. 2, the electrostatic powder coating apparatus 20 may include an jet flow generating element 21, an electric field generating element 22, an electric field shaping element 23, and a main body structure 25. among them:

The jet stream generating element 21 is disposed in the inner cavity of the main body structure 25, and the electric field generating element 22 is disposed on a side of the main body structure 25 adjacent to the element 30 to be painted, and the electric field shaping element 23 is sleeved on the periphery of the electric field generating element 22 and with the main body structure 25. Removable connection. This embodiment is preferably electric field shaping The element 23 is an insulating package provided in a tubular shape, and preferably the insulating set is made of a high-impedance insulating material such as PTFE (Polytetrafluoroethylene, Teflon, Teflon, Teflon) or ceramic.

The jet stream generating member 21 may include a discharge electrode needle 211, and a discharge electrode needle 211 of the jet stream generating member 21 is disposed inside the insulating kit for forming charged powder particles.

When the electrostatic powder spraying device 20 performs the dusting operation on the component to be painted 30 conveyed on the conveying guide 40, the main structure 25 is grounded and the holding portion turns on the high-voltage static electricity, introduces the spray powder and the compressed air, and the electric field generating element 22 can be used for the connection. High voltage static electricity is generated and an electrostatic force field is generated between the electric field generating element 22 and the element to be painted 30.

The jet stream generating member 21 can be used for ejecting sprayed powder and compressed air. When sprayed, the sprayed powder is negatively charged by the electrostatic force field to form charged powder particles, mixed in compressed air to form an jet stream and sprayed by the jet stream generating member 21. Out.

The electric field shaping element 23 can be used to shape the electrostatic force field between the electric field generating element 22 and the element to be painted 30 to reduce the electrostatic shielding effect of the electrostatic force on the Faraday cage around the recessed area 31 of the component to be painted, so that the electrostatic force field The charged powder particles can be guided to deposit on the recessed regions 31 of the component 30 to be painted. Specifically, in a dimension perpendicular to the movement axis A of the jet stream, the electric field distribution region of the electrostatic force field shaped by the electric field shaping member 23 is smaller than the electric field distribution region of the electrostatic force field not shaped by the electric field shaping member 23.

In this embodiment, it is preferred that the motion axis A of the jet stream is on the same line as the discharge electrode needle 211, and preferably one dimension is the Y-axis in the spatial three-dimensional Cartesian coordinate system. Of course, in other embodiments, according to the arrangement shape of the insulation kit, the electric field distribution area of the electrostatic force field shaped by the electric field shaping element 23 may be smaller than the electric field shaping in a plurality of dimensions perpendicular to the movement axis A of the jet stream. The electric field distribution region of the electrostatic force field shaped by the element 23, wherein the plurality of dimensions may further include an X-axis, a Y-axis, and a Z-axis in the spatial three-dimensional Cartesian coordinate system.

Further, the size of the insulating kit in at least one dimension is smaller than the dimension of the recessed region 31 in the corresponding dimension (Y-axis), for example, the width of the insulating sleeve is smaller than the width of the recessed region 31. Also, the free end of the insulating set (the one end facing the recessed area 31) is provided to be able to protrude into the inside of the recessed area 31 of the member to be painted 30, so that the jet flow can be guided to the inside of the recessed area 31.

This embodiment can insulate according to the outer shape of the component to be painted 30 and the recessed area 31. The free end of the kit is processed into various shapes such as a tip, a flat mouth, etc., which can directly protrude into the inside of the recessed area 31, and the purpose thereof is to directly transport the charged powder particles to the inside of the recessed area 31 to complete uniform spraying, thereby solving the above problem. The third problem is that the sprayed powder (charged powder particles) can be efficiently guided to the inside of the recessed portion 31 even if the recessed portion 31 is a semi-closed chamber which is difficult to enter even with air.

Based on the above, it is understood that the electric field shaping member 23 (insulation kit) is formed as an isolating jacket according to the outer shape of the electrostatic powder coating device 20, and the insulating property is utilized to isolate the strong generated between the electric field generating member 22 and the member to be painted 30. The electrostatic force field can thereby prevent the Faraday cage electrostatic shielding effect from occurring around the recessed area 31 (at the edge).

Moreover, since the electric field generating element 22 and the discharge electrode pin 211 are disposed inside the insulating package, which is equivalent to changing the external discharge to the internal discharge mode, the second problem can be solved to cause the spray powder to be subjected to high-voltage static electricity, and The first problem is solved in that the high-voltage electrostatic force field generated by the discharge of the discharge electrode needle 211 between the electric field generating element 22 and the element to be painted 30 is prevented, so that the spray powder can be effectively guided to the inside of the recessed area 31. The powder depth in the recessed region 31 is increased, and the electrostatic powder coating device 20 can uniformly powder the recessed region 31 having an aspect ratio of 10:1 or more in practical use.

Referring again to FIG. 3, the electrostatic powder coating apparatus 20 can further include a flow directing element 24 that can be used to reduce the jet flow rate. Moreover, it is preferable that the flow guiding member 24 is disposed on the inner wall of the first region D1 of the insulating package, and of course may be disposed in the second region D2 of the insulating package, wherein the diameter of the first region D1 is smaller than the diameter of the second region D2.

For example, in this embodiment, the flow guiding element 24 is preferably a spiral structure and is integrally formed with an insulating package. The spiral flow guiding element 24 is configured to guide the jet airflow to spirally move around the movement axis, thereby slowing the jet flow. The flow rate, which reduces the rebound of the charged powder particles in the interior of the recessed region 31, is not limited to the bottom of the recessed region 31 and the sidewall sandwiched at the bottom, thereby increasing the deposition of the charged powder particles inside the recessed region 31, and enhancing the recessed region 31. The rate of powdering.

It should be noted that the various structures in the electrostatic powder coating device 20 shown in FIG. 2 can be configured. For example, the first region D1 of the insulating package can be disposed only as two upper and lower plates, or the interface is triangular, and the flow guiding member 24 Other structures may be provided, and are not limited to the spiral structure shown in FIG. 3 as long as the flow velocity of the jet stream can be slowed down, and the rebound of the charged powder particles inside the recessed region 31 can be reduced.

In the following, the actual application scenario shown in FIG. 4 is taken as an example of the "heat dissipating teeth" as shown in FIG. 4, and the electrostatic powder coating device 20 of the present embodiment and the high-voltage static electricity in the prior art are respectively used. The dusting gun 10 is sprayed for about 3.5 minutes. After the powder is solidified, the thickness of the coating from position 1 to position 17 is measured by means of a film thickness gauge and slicing. The data in Table 1 below is provided by the present embodiment. The coating thickness data obtained by the electrostatic powder coating apparatus 20, the data in the following Table 2 is the coating thickness data obtained by the electrostatic powder coating apparatus 10 of the prior art, and the numerical unit in Table 1 and Table 2 is micrometer.

位置 position	11	22	33	44	55
位置 position	11	22	33	44	55	涂层厚度Coating thickness	172～177172-177	116～126116～126	170～189170～189	187～225187~225	93～16593～165
位置 position	66	77	88	99	1010	涂层厚度Coating thickness	172～177172-177	116～126116～126	170～189170～189	187～225187~225	93～16593～165
位置 position	66	77	88	99	1010	涂层厚度Coating thickness	104～118104～118	108～127108～127	129～148129～148	104～131104～131	154～201154~201
位置 position	1111	1212	1313	1414	1515	涂层厚度Coating thickness	104～118104～118	108～127108～127	129～148129～148	104～131104～131	154～201154~201
位置 position	1111	1212	1313	1414	1515	涂层厚度Coating thickness	89～9589～95	159～170159~170	248～253248~253	206～262206~262	154～208154~208
位置position	1616	1717				涂层厚度Coating thickness	89～9589～95	159～170159~170	248～253248~253	206～262206~262	154～208154~208
位置position	1616	1717				涂层厚度Coating thickness	243～272243-272	81～8581～85

Table 1

位置 position	11	22	33	44	55
位置 position	11	22	33	44	55	涂层厚度Coating thickness	129～157129～157	90～11490～114	161～185161~185	0～360 to 36	8～658～65
位置 position	66	77	88	99	1010	涂层厚度Coating thickness	129～157129～157	90～11490～114	161～185161~185	0～360 to 36	8～658～65
位置 position	66	77	88	99	1010	涂层厚度Coating thickness	18～5218～52	80～9280～92	84～10684～106	119～122119～122	113～117113～117
位置 position	1111	1212	1313	1414	1515	涂层厚度Coating thickness	18～5218～52	80～9280～92	84～10684～106	119～122119～122	113～117113～117
位置 position	1111	1212	1313	1414	1515	涂层厚度Coating thickness	76～9376～93	88～10588～105	200～217200～217	16～5816~58	110～150110～150
位置position	1616	1717				涂层厚度Coating thickness	76～9376～93	88～10588～105	200～217200～217	16～5816~58	110～150110～150
位置position	1616	1717				涂层厚度Coating thickness	109～130109～130	133～152133-152

Table 2

As shown in FIG. 5, the first section along the line A-A of the component to be painted 30 is referred to Table 1. The thickness of the coating formed by curing at the position 1 after the dusting by the electrostatic powder spraying device 20 provided in this embodiment is 172 to 177 micrometers, and the thickness of the coating formed by curing at the position 2 is 116 to 126 micrometers, and the position is cured at 3 places. The thickness of the coating formed is 170 to 189 microns, and the thickness of the coating formed by curing at the position 4 is 187 to 225 microns. Referring to Table 2, when the high-pressure electrostatic spray gun 10 of the prior art is used, the thickness of the coating formed by curing at the position 1 is 129 to 157 μm, and the thickness of the coating formed by curing at the position 2 is 90 to 114 μm, and the position 3 The thickness of the coating formed by curing is 161 to 185 micrometers, and the thickness of the coating formed by curing at the position 4 is 0 to 36 micrometers.

As shown in FIG. 6, at the second section along the BB line of the component to be painted 30, with reference to Table 1, the thickness of the coating formed by curing at the position 5 after the powder is sprayed by the electrostatic powder coating device 20 provided in this embodiment is 93 to 165 microns, the thickness of the coating formed by curing at position 6 is 104 to 118 microns, the thickness of the coating formed by curing at position 7 is 108 to 127 microns, and the thickness of the coating formed by curing at position 8 is 129 to 148 microns. Referring to Table 2, when the high-pressure electrostatic spray gun 10 of the prior art is used, the thickness of the coating formed at the position 5 is 8 to 65 μm, and the thickness of the coating formed at the position 6 is 18 to 52 μm. The thickness of the coating formed by curing is 80 to 92 μm, and the thickness of the coating formed by curing at position 8 is 84 to 106 μm.

As shown in FIG. 7, at the third section along the CC line of the component to be painted 30, referring to Table 1, the thickness of the coating formed by curing at the position 9 after the powder is sprayed by the electrostatic powder coating device 20 provided in this embodiment is The thickness of the coating formed by curing at position 10 is 154 to 201 μm, the thickness of the coating formed by curing at the position 11 is 89 to 95 μm, and the thickness of the coating formed by curing at the position 12 is 159 to 170 μm. Referring to Table 2, when the high-pressure electrostatic spray gun 10 of the prior art is used, the thickness of the coating formed by curing at the position 9 is 119-122 micrometers, and the thickness of the coating formed by curing at the position 10 is 113-117 micrometers, position 11 The thickness of the coating formed by curing is 76 to 93 μm, and the thickness of the coating formed by curing at the position 12 is 88 to 105 μm.

As shown in FIG. 8, at the fourth section along the DD line of the component to be painted 30, referring to Table 1, the thickness of the coating formed by curing at the position 13 after the powder is sprayed by the electrostatic powder coating device 20 provided in this embodiment is 248 ~ 253 microns, the thickness of the coating formed by curing at position 14 is 206 ~ 262 microns, the thickness of the coating formed by curing at position 15 is 154 ~ 208 microns, and the thickness of the coating formed by curing at position 16 is 243 ~ 272 microns. The thickness of the coating formed by curing at point 17 is 81-85 μm. Referring to Table 2, when the high-pressure electrostatic spray gun 10 of the prior art is used, the thickness of the coating formed by curing at the position 13 is 200 to 217 μm, and the position is 14 The thickness of the coating formed by curing is 16 to 58 microns. The thickness of the coating formed by curing at the position 15 is 110 to 150 μm, the thickness of the coating formed by curing at the position 16 is 109 to 130 μm, and the thickness of the coating formed by curing at the point 17 is 133 to 152 μm.

From the comparison of the data in Table 1 and Table 2, it is known that at position 4, position 5, position 6, and position 14, the thickness of the coating formed by solidifying the recessed region 31 by the electrostatic powder coating device 20 of the embodiment of the present invention is used. It is much larger than the thickness of the coating formed by solidification in the recessed region 31 when the high-voltage electrostatic powder gun 10 of the prior art is used. Moreover, the greater the depth of the recessed region 31, the smaller the thickness of the coating formed by curing when the high-voltage electrostatic powder gun 10 of the prior art is used, and the embodiment of the present invention is formed by solidification at the recessed region 31 (at position 4 and position 17). The coating thickness is still able to meet the production standard of 80 to 140 microns.

Figure 9-14 shows a microscopic enlarged view of the powder coating formed at the 4, 5, and 14 positions when using the high-voltage electrostatic spray gun 10 of the prior art, the magnification is 100 times, from Figure 9- 14 and the comparison of the data of Tables 1 and 2, it can be seen that the thickness of the coating formed by the electrostatic powder spraying device 20 of the embodiment of the present invention when the recessed region 31 is cured is much higher than that of the prior art. When the powder gun 10 is cured, the thickness of the coating formed in the recessed region 31 is more uniform.

The embodiment of the invention also provides an electrostatic powder coating method as shown in FIG. Referring to FIG. 15, the electrostatic powder coating method of this embodiment may include:

Step S41: An electrostatic force field is generated between the electric field generating element and the element to be painted.

Step S42: shaping the electrostatic force field by using the electric field shaping element.

Step S43: guiding the charged powder particles in the jet stream to the recessed area of the component to be painted by using the shaped electrostatic force field.

Wherein, the electrostatic force field formed by the electric field shaping element is generated in the Faraday cage of the Faraday cage of the component to be painted, and the electrostatic shielding field generated by the electric field shaping component is smaller than the electrostatic force field formed by the electric field shaping component. Electrostatic shielding effect.

Specifically, the charged powder particles are formed by the discharge electrode needle, and the electric field distribution region of the electrostatic force field shaped by the electric field shaping element is smaller than the static shape of the electric field shaping element in at least one dimension perpendicular to the movement axis of the jet airflow. The electric field distribution region of the electric field, wherein preferably the motion axis of the jet stream is on the same line as the discharge needle, and at least one dimension may comprise the X-axis, the Y-axis, and the Z-axis in the spatial three-dimensional Cartesian coordinate system.

In this embodiment, the electrostatic force field is preferably shaped by an insulation kit sleeved on the periphery of the electric field generating element, and the insulating sleeve is arranged in a tubular shape, and the electrode needle is disposed in the insulation kit. internal. Additionally, the size of the insulating set in at least one dimension is less than the dimension of the recessed area in the corresponding dimension.

Preferably, the above-described insulating kit can be used to guide the jet stream to the inside of the recessed area.

Further, the embodiment preferably utilizes a flow guiding element for guiding the jet airflow to spirally move along the movement axis, and the flow guiding element may be a spiral structure and integrally formed with the insulation kit for guiding the jet airflow around the movement axis. The spiral motion reduces the flow velocity of the jet stream and reduces the rebound of the charged powder particles inside the recessed region 31.

The electrostatic powder coating method of the present embodiment is based on the electrostatic powder coating device 20 of the embodiment shown in FIG. 2, and the specific process of spraying is not repeated herein.

It is to be noted that the above description is only an embodiment of the present invention, and thus does not limit the scope of the invention, and the equivalent structure or equivalent flow transformation using the description of the present invention and the drawings, for example, the technology between the embodiments The combination of features, or directly or indirectly, in other related technical fields, is equally included in the scope of patent protection of the present invention.

Claims

An electrostatic powder spraying device, characterized in that the electrostatic powder spraying device comprises:

a jet stream generating element for generating a jet stream carrying charged powder particles;

a flow guiding element for guiding the jet airflow to spirally move about its movement axis;

An electric field generating element for generating an electrostatic force field for guiding the charged powder particles between the electric field generating element and the element to be painted;

An electric field shaping component for shaping the electrostatic force field to reduce the electrostatic shielding effect of the electrostatic force on the Faraday cage around the recessed area of the component to be painted, wherein

The electric field shaping element is an insulating sleeve sleeved on a periphery of the electric field generating element, and a free end of the insulating sleeve is disposed to extend into a recessed area of the component to be painted, thereby injecting the jet stream Leading to the interior of the recessed region, and in at least one dimension perpendicular to the axis of motion of the jet stream, the electric field distribution region of the electrostatic force field shaped by the electric field shaping element is less than An electric field distribution region of the electrostatic force field shaped by the electric field shaping element.
The electrostatic powder coating apparatus according to claim 1, wherein a dimension of said insulating package in said at least one dimension is smaller than a dimension of said recessed area in said corresponding dimension.
The electrostatic powder coating apparatus according to claim 3, wherein said insulating kit is provided in a tubular shape.
The electrostatic powder coating apparatus according to claim 1, wherein said jet stream generating member further comprises a discharge electrode needle for forming said charged powder particles, wherein said discharge electrode needle is provided to said insulating kit internal.
An electrostatic powder spraying device, characterized in that the electrostatic powder spraying device comprises:

a jet stream generating element for generating a jet stream carrying charged powder particles;

An electric field generating element for generating an electrostatic force field for guiding the charged powder particles between the electric field generating element and the element to be painted;

And an electric field shaping component for shaping the electrostatic force field to reduce the electrostatic shielding effect of the electrostatic force on the Faraday cage around the recessed area of the component to be painted.
The electrostatic powder coating apparatus according to claim 5, wherein said electric field The shaping element is an insulating kit that is sleeved around the periphery of the electric field generating element.
The electrostatic powder coating apparatus according to claim 6, wherein an electric field distribution region of said electrostatic force field shaped by said electric field shaping element is formed in at least one dimension perpendicular to a movement axis of said jet stream An electric field distribution region that is smaller than the electrostatic force field that is not shaped by the electric field shaping element.
The electrostatic powder coating apparatus according to claim 7, wherein a dimension of said insulating sheath in said at least one dimension is smaller than a dimension of said recessed region in said corresponding dimension.
The electrostatic powder coating apparatus according to claim 8, wherein said insulating set is in a tubular arrangement.
The electrostatic powder coating apparatus according to claim 6, wherein said jet stream generating member further comprises a discharge electrode needle for forming said charged powder particles, wherein said discharge electrode needle is provided to said insulating kit internal.
The electrostatic powder coating apparatus according to claim 6, wherein said free end of said insulating member is disposed to extend into an interior of said recessed portion of said member to be painted, thereby guiding said jet stream to said The interior of the recessed area.
The electrostatic powder coating apparatus according to claim 5, wherein said electrostatic powder spraying device further comprises a flow guiding member for guiding said injection gas stream to spirally move about a movement axis.
An electrostatic powder coating method, characterized in that the electrostatic powder coating method comprises:

Generating an electrostatic force field between the electric field generating element and the component to be painted;

Forming the electrostatic force field using an electric field shaping element;

Using the electrostatic force field after shaping to guide charged powder particles in the jet stream to the recessed area of the component to be painted,

Wherein the electrostatic force field formed by the electric field shaping element is generated in a Faraday cage electrostatic shielding effect around the recessed area of the component to be painted is smaller than the electrostatic force field not shaped by the electric field shaping element The electrostatic shielding effect of the Faraday cage generated around the recessed area of the sprayed component is described.
The electrostatic powder coating method according to claim 13, wherein the step of shaping the electrostatic force field by using an electric field shaping element comprises:

The electrostatic force field is shaped using an insulation kit that is placed around the periphery of the electric field generating element.
The electrostatic powder coating method according to claim 14, wherein the step of shaping the electrostatic force field by using an insulating kit sleeved around a periphery of the electric field generating element comprises:

An electric field distribution region of the electrostatic force field shaped by the electric field shaping element is smaller than at least one dimension perpendicular to a motion axis of the jet stream, and the electrostatic force field not shaped by the electric field shaping element Electric field distribution area.
The electrostatic powder coating method according to claim 15, wherein a dimension of the insulating package in the at least one dimension is smaller than a dimension of the recessed region in a corresponding dimension.
The electrostatic powder coating method according to claim 16, wherein the insulating set is in a tubular arrangement.
The electrostatic powder coating method according to claim 14, wherein said step of using said shaped electrostatic force field to direct charged powder particles in the jet stream to said recessed region of said member to be sprayed is further include:

The charged powder particles are formed by a discharge electrode provided inside the insulating kit.
The electrostatic powder coating method according to claim 14, wherein the step of guiding the charged powder particles in the jet stream to the recessed region of the component to be sprayed by using the shaped electrostatic force field comprises:

The jet stream is directed to the interior of the recessed area using the insulating kit.
The electrostatic powder coating method according to claim 13, wherein the step of guiding the charged powder particles in the jet stream to the recessed region of the component to be sprayed by using the shaped electrostatic force field comprises:

A flow guiding element is used for guiding the jetted airflow to move helically along the axis of motion.