CN1105608A

CN1105608A - Electrostatic powder spraying apparatus

Info

Publication number: CN1105608A
Application number: CN94114902A
Authority: CN
Inventors: 卡尔·布斯考
Original assignee: GEMA-VOLSTATIC AG
Current assignee: GEMA-VOLSTATIC AG; Gema Switzerland GmbH
Priority date: 1993-08-02
Filing date: 1994-07-30
Publication date: 1995-07-26
Also published as: EP0637466A1; EP0637466B1; DE4325911A1; DE59405564D1; ATE164535T1

Abstract

Electrostatic powder-spraying device with a charging electrode (20) for the electrostatic charging of powder for the spray-coating of articles and with at least one counterelectrode (52) for the electrostatic extraction of free ions from the stream of sprayed powder. An electrical conduction path for connecting the counterelectrode (52) to a different electrical potential from the charging electrode (20) contains a ring-contact connection (68). The powder-spraying device can be demounted in a simple way for cleaning and can also optionally be used without a counterelectrode .

Description

Electrodusting device

The present invention relates to a kind of as the said electrodusting device of preface in the claim 1.

This powder spraying apparatus has one to be used for from the counter electrode of the stream sucking-off free ion that dusts.A kind of like this electrodusting device is open by U.S. Pat-PS4921172 number.The powder spraying apparatus of the disclosure has the body of more than one formation, has a powder channel to pass this body, is provided with a spout so that powder is sprayed on the object that will cover in its downstream.In the upstream of spout, but powder channel radially outside be provided with the counter electrode of a ring-type, this electrode is tightened on the end face that is resisted against body vertically with a threaded sleeve.There is a helical spring to be stretched between the part of counter electrode and body back and with these two mutual electric connections of part.After-Body is a ground connection.This helical spring is located at one with one heart in the endless groove around powder channel.Helical spring can be connected with other current potentials as not being connected with earth potential also.As long as this current potential can cause enough potential difference between counter electrode and one charging electrode with the powder charging, just the free ion in the powder to be painted that flows to counter electrode can being flowed by this potential difference sops up with electrostatic methods.

Counter electrode was also once disclosed by U.S. Pat-PS4774102.

One or more charging electrodes that are used for the powder static electricity charging can or be located at thereafter before powder stream sprays among the powder stream or near it.Charging electrode is connected with the high voltage that is generally between the 10KV to 110KV.This high voltage is taken place by a high pressure generator, and this generator can constitute one with powder spraying apparatus or be connected in the outside.The object that covers is connected to another current potential, is generally earth potential.Free ion arrives on the object that will cover with the powder of ejection.Acting as before free ion arrives the object that will cover of counter electrode with its sucking-off from powder stream.In most cases, remove free ion and can obtain covering quality preferably.After overwrite procedure finishes the object that is capped sent in the stove and handle, powder particle is melted in together in this stove, constitutes a uniform coating.

Its shape is as the body of a lengthwise when electrodusting device is used as the equipment of control automatically, and its shape is as a pistol when as hand-held.

According to the kind of the object that will cover and the tectal kind of wanting, may be the powder spraying apparatus that has counter electrode under certain conditions, may be the powder spraying apparatus of not being with counter electrode also in another case, the coverage effect that draws is better.

Also have such operating position in addition, for example when covering the pit of an object, change the cross section of jet hole into slit-shaped by circle and can obtain coverage effect preferably with spraying.

Now, the high voltage that charging electrode is used generally is not to produce with the high pressure generator that is located at the outside, but uses high pressure generator in powder spraying apparatus is contained in body to produce.According to the difference of operating position, may adopt a high voltage or a lower high voltage comparatively suitable.In other words, according to the difference of operating position, wish that powder spraying apparatus has a higher or lower voltage.Known for this purpose such formation electrodusting device is even high pressure generator is removable.

A kind of powder spraying apparatus with integrant removable high pressure generator is disclosed by U.S. Pat-PS4196465 number.

The objective of the invention is to construct a kind of electrodusting device, it can take apart rapidly to lay equal stress on and newly install with straightforward procedure.It should be able to freely select to have in use and still not be with counter electrode with straightforward procedure in addition.In addition, it also should be able to promptly be changed with another powder jet with another high pressure generator and/or with a powder jet with its all-in-one-piece high pressure generator one with simple method.

These purposes are to solve by the listed feature of characteristic in the claim 1 according to the present invention.

Other feature of the present invention is listed respectively in the dependent claims.

As demonstration the present invention is described with a plurality of embodiment below in conjunction with accompanying drawing.In the accompanying drawings:

The longitudinal sectional drawing that Fig. 1 cuts open when having counter electrode vertically for powder spraying apparatus of the present invention;

Fig. 2 is for seeing the zoomed-in view of the electric contactor of a ring-type contact device by the direction of arrow II in Fig. 1;

Fig. 3 is the state of contactor when turn-off among Fig. 2, just can screw out with rear sleeve at this;

Fig. 4 is provided with a sleeve pipe for the lengthwise profile of cutting open vertically of the amplification of another embodiment of powder spraying apparatus of the present invention on this equipment, be loaded with counter electrode on it;

Fig. 5 is the longitudinal sectional drawing vertically of the powder spraying apparatus among Fig. 3, and sleeve pipe is changed, and is not with counter electrode on it.

The electrodusting device that draws in the drawings contains a body 4 of being made by electrically insulating material, a pipe of walking vertically 8 of making by electrically insulating material, one powder flow down trip and body 4 and manage 8 middlewares that are connected 12 and one be connected the nozzle 10 that powder flows downstream part, also all make for these two by electrically insulating material.Pipe 8, middleware 12, a lining 6 and the nozzle 10 around it constitute a powder channel 14, by this passage powder can from one powder stream back, upstream be contained in that equipment part 15 usefulness strengths on the body 4 are transported to nozzle 10 and by spout 18 ejections that are located on the nozzle 10.Powder will be sprayed on the object that will cover by spout 10.Middleware 12 extends a segment distance in powder channel 14, its shape is as a narrow boards, so powder can flow through on the next door of middleware 12 vertically.The charging electrode 20 of a needle-like is housed on middleware 12, its electrode tip 21 in the air duct 24 that is located on the middleware 12 to outside be projected into spout 18 updrift side nearby.The compressed air of being introduced by air duct 24 flows through on the next door of electrode tip 21 and flows in the powder channel 14 and enter spout 18.Charging electrode 20 is along the axial setting of powder channel 14, and the electric plug connector 28 that connects at powder stream upstream end by at least one resistance 26 and in the rear end of its powder stream updrift side is connected with the high-voltage output end 30 of the front of a high pressure generator 32 with 29.The known cascade circuit that high pressure generator preferably is made up of resistance and electric capacity.This high pressure generator for example U.S. Pat-PS4195465 number disclosed.High pressure generator 32 have one at the low pressure input of back so that be connected with outside low-tension supply.High pressure generator 32 is placed in the cavity 36 that constitutes on body 4, and this cavity 36 extends abreast with powder channel 14, and leads to body 4 flows down trip at powder a end face 48.Extract middleware 12 vertically, plug-in

connector

28 and 29 is thrown off.At this moment cavity 36 opens wide to middleware 12, and therefore after plug-in

connector

28,29 was thrown off, high pressure generator 32 can be changed another high pressure generator again from extraction in the cavity 36.The high-tension electricity that high pressure generator takes place acts on the electrode 20 and by the air in its next door air flowing passage 24 and makes powder fill static with.

On body 4, be provided with external screw thread 40, can twist thereon by the sleeve pipe that is provided with internal thread 42 that electrically insulating material is made.Sleeve pipe 42 inserts by nozzle 10, and is pressed on the radial end face 46 of a directed forward on the nozzle 10 with its radial end face 44 that points to the rear.Therefore sleeve pipe 42 is pressed on the radial end face 48 of body 4 fronts nozzle 10 and middleware 12 with its radial end face 44.Only sleeve pipe 42 need be turned on from body 4 when taking out nozzle 10, middleware 12 and high pressure generator 32 and be got final product.

Sleeve pipe 42 is crossed and is become a casing section 50 behind its female thread portion and extend back.This casing section 50 in screw thread 41 back is equipped with a plurality of needle-like counter electrodes 52 that ring-type is arranged around powder channel 14 that become.Counter electrode 52 is located within the radial hole 56 that constitutes on the casing section 50, and the outer surface of casing section 50 is led in this hole 56.Radial hole 56 is connected with a compressed air source by annular channel 57 that they are coupled together on the sleeve pipe 42, and its compressed air stream floods these counter electrodes 52, thereby general dust is blocked in outside the counter electrode 52.Basically it is the radial inner end that always extends to counter electrode 52 from the electrical connector 62 at equipment part 15 back sides that are contained in the back that parallel with powder channel 14 conductive path 60 is arranged, make counter electrode 52 can pass through electrical connector 62 and a current potential, preferably earth potential connects.This current potential is different with the high potential of charging electrode 20, so counter electrode 52 can attract the free ion that spout 18 downstream parts dust in the stream to come, and makes their eliminate electric charge by conductive path 60 and connector 62 then.As close as possible spout 18 is answered in the position of counter electrode 52, to obtain best electrical efficiency.But be located at the upstream end of spout 18 in practice as shown in Figure 1, with one heart but outside powder channel 14 around powder channel 14.It should be noted that, be located at upstream end and leave spout 18 rears far away like this, still can from the stream that dusts, sop up abundant free ion, but powder particle can not be deposited on the

counter electrode

52,52 spark discharge can not take place from charging electrode 20 to counter electrode simultaneously yet.Except adopting a plurality of counter electrodes 52, also can adopt single unique counter electrode 52, at this moment its shape is preferably made the ring-type coaxial with sleeve pipe 42.In another form of implementation, the also available conductive material of sleeve pipe 42 is made, and itself is just as counter electrode.

The direction that conductive path 60 flows in powder channel 14 according to powder is divided into the preceding conducting line segment 66 that conducting line segment 64 and powder behind the powder stream upstream flow down trip.These two conducting

line segments

64 and 66 contact connector 68 by a ring-type and mainly are made of a contact ring 70 and a contactor 72 made from conductive material.Contactor 72 is close on the contact ring 70 and with back conducting line segment 64 and is communicated with on circuit.Contact ring 70 is fixedly placed near being communicated with on circuit on the inner peripheral surface 74 of casing section 50 rear ends of back and with preceding conducting line segment 66.Preceding conducting line segment parallel on the axis with powder channel 14 be concentric mutually at two and two surfaces that adjoin each other 78 of the pipe 80 that is mutually permanently connected and 81 and 79 between extension, they together constitute the casing section 50 of back, contact ring 70 rotates around powder channel 14 with one heart with sleeve pipe 42 when sleeve pipe 42 being screwed on or turn on, and contactor 72 does not rotate.Contactor 72 is located in the recessed shelves 84 that constitute on body 4 outer surfaces, the position is 63 mouth limit in the hole, and is communicated with on circuit by a guide rod 64 of being made by conductive material, and this guide rod 64 passes hole 63, constitute the part of back conducting line segment 64, and on circuit, be communicated with connector 62.Guide rod 64 constitutes a plug-in connector with connector 62.Hole 63 constitutes on body 4, and its trend is parallel with powder channel 14.Ke Zhuandong contactor 72 is not contained on the body 4 securely and from inside to outside is close on the contact ring 70.Guide rod 64 in hole 63 stops contactor 72 not allow it rotate around powder channel 14.On the contactor 72 that contact ring 70 and casing section 50 cannot not be overlapped on rotatablely.Though contactor 72 can not rotate around powder channel 14, but is adorning securely, it can both mechanically with electrically contact with contact ring 70 in each turned position of sleeve pipe 42, because contact ring 70 is to extend on the whole inner periphery of sleeve pipe 42.

When with sleeve pipe 42 contactor 72 releasables when body 4 is turned on, this moment, contactor 72 can outwards be extracted forward from body together with guide rod 64.By the taking-up of the guide rod 64 of conducting line segment after contactor 72 and the formation, can guarantee when powder spraying apparatus does not use with counter electrode 52, spark discharge can not take place the lead-through 72,64 of a conduction of 52 from charging electrode 20 to counter electrode.Therefore not with counter electrode 52 time, must be noted that those are connected element with charging electrode 20 different potentials, for example contactor 72 and guide rod 64 are arranged to such an extent that leave charging electrode 20 and enough distances are arranged so that the high-tension electricity of charging electrode 20 can not jumped on these elements 72 and 64.But safe and the simplest way is that contactor 72 and guide rod 64 are taken out from powder spraying apparatus.

In the recessed shelves 84 of body 4 outsides, also be provided with an axial link stopper 86, contactor 72 can rotate to the rear of block around the axis of guide rod 64, the back that also can be placed on block is by sleeve pipe 42 clampings, thereby contactor 72 is because the mouth limit in hole 63 and axial stop 86 can remain on an axial location that contact ring 70 is determined.When sleeve pipe 42 contactor 72 when body 4 is turned on just being left axial stop 86 around the axis of guide rod 64 and outwards rotating, just can extract from body 4 vertically subsequently together with guide rod 64.

Figure 2 shows that the contactor 72 that the direction of arrow II from Fig. 1 is looked and the situation of guide rod 64, contactor 72 is in the operating position of a locking in the back of axial stop 86 at that time.Figure 3 shows that the contactor 72 among Fig. 2 is in a situation of taking the position away of freeing, this position contactor 72 can sleeve pipe 42 take away the back according to Fig. 2 in directional ring shown in the arrow 88 leave axial stop around the axis of guide rod 64 and outwards rotate.In Fig. 3 free take on the position contactor 72 away and can leave axial stop 86 together with guide rod 64 and outwards extract forward on 4 along the direction that is parallel to powder channel 14 from body.

The contactor 72 rotatable with respect to contact ring 70 be by a contact shell of making by conductive material 90, ring that contact with contact ring 70 of making by conductive material 91, one be screwed into contact shell 90 interior bolt 92 and springs 93 and constitute, the two is also all made by conductive material.Spring 93 is stretched between bolt 92 and the contact ring 91 and flexibly contact ring 91 is pressed on the contact ring 70.Thereby the guide rod that constitutes back conducting line segment 64 be make by conductive material and mechanically be connected with contact shell 90 and contact ball 91 and on circuit, be communicated with.

Nozzle 10 can be changed with another has spout 18 circular or slit-shaped on cross section nozzle 10 when taking sheath body 42 away with straightforward procedure.

Another sleeve pipe 142 of sleeve pipe 42 usefulness that counter electrode 52 preferably will be housed when not using powder spraying apparatus with counter electrode 52 is changed as shown in Figure 5 not with counter electrode 52.

Can not forget at that time, using another not before the sleeve pipe 142 with counter electrode 52, contactor 72 and the back conducting line segment 64 with guide rod shape are removed, this is the measure according to the assurance safety of the present invention's regulation, only after contactor 72 and back conducting line segment 64 being removed, another sleeve pipe 142 could be fastened on the powder spraying apparatus in advance.This measure also may exist in other places, for example on the sleeve pipe that is provided with one or more counter electrodes 52 42 shown in Figure 4, the end section 146 at its rear portion has the interior diameter 147 of increase, and this interior diameter 147 is greater than the interior diameter 150 that is not had on its posterior end section with the sleeve pipe 142 of counter electrode 52 shown in Figure 5.Like this contact ring 70 just with the position on the interior diameter 147 of the increase on the end section 146, and contactor 72 will extend on the end section 146 with till contact ring 70 contacts.Thereby another sleeve pipe 142 among Fig. 5 just can not slide on contactor 72.Only after contactor 72 and guide rod 64 being taken out in the powder spraying apparatus, could correctly another sleeve pipe 142 be fastened on the body 4 in advance.

Claims

1. electrodusting device has: a body (4); Article one, powder channel (14) runs through body (4) and is used for pneumatic transmission powder; The powder that a spout (18) is contained in powder channel (14) flows downstream so that powder is sprayed on the object that will cover; At least one charging electrode (20) is used for making powder fill static with high-tension electricity near spout (18); At least one counter electrode (52) radially is located at outside the powder stream spaced apart with charging electrode; Article one, conductive path (60) extends to counter electrode (52) always and is connected with an electronegative potential from the electrical connector (62) on body (4) rear portion of powder stream updrift side, makes counter electrode (52) sop up the free ion of powder to be painted in flowing with electrostatic force by this conductive path (60); It is characterized in that,

Conductive path (60) is divided into one and electrical connector (62) conducting line segment (64) and one and counter electrode (52) conducting line segment (66) before circuit is coconnected after circuit is coconnected; This two conducting line segment (64,66) releasably on circuit, link together by a ring-type contact device (68), this ring-type contact device (68) has a contact ring around powder channel (14) that separates diametrically (70) and a contactor that contacts with it (72), one of them contact part (70) can rotate around powder channel (14), and another contact part (72) relatively cannot not said so rotatablely, wherein rotating contact part (70) is electrically connected with preceding conducting line segment (66), and not rotatable contact part is electrically connected with back conducting line segment (64); Be provided with one and can pass in and out the sleeve pipe (42) of loading onto and taking out at body (4), on this sleeve pipe (42), be provided with the rotatable part (70) of counter electrode (52), preceding conducting line segment (66) and annular contact device (68) from spout (18); On body (4) and sleeve pipe (42), be provided with rotational coupling mechanism (40,41), utilize this mechanism (40,41) rotating casings (42) just it can be fastened on the body (4), and can take off from body (4) by counter-rotation; It all is to be placed in the body (4) at the coconnected rotatable part (72) that contacts of circuit that back conducting line segment (64) reaches with it with taking out, but near taking-up path is stopped up as long as sleeve pipe (42) is fastened on body (72).

2. according to the electrostatic dusting device of claim 1, it is characterized in that:

Be provided with a nozzle (10) with spout (18), sleeve pipe (42) is overlapped on the nozzle (10) and nozzle (10) is remained on axial between sleeve pipe (42) and the body (4) precalculated position.

3. each electrodusting device is characterized in that in requiring according to aforesaid right,

Sleeve pipe (42) is made of at least two concentric tubes that are fixed together (80,81), is extending from ring-type contact connector (68) rotating contact part (70) through to the preceding conducting line segment (66) of counter electrode (52) between two pipes (80,81).

4. each electrodusting device is characterized in that in requiring according to aforesaid right,

Sleeve pipe (42) is provided with internal thread (41), therefore can be screwed on the external screw thread (40) of body (4).

5. each electrodusting device is characterized in that in requiring according to aforesaid right,

The not rotatable contact part (72) of ring-type contact device (68) can turn to the back two of the last axial stop of body (4) (86) and enter mode of operation around a longitudinal axis on the back conducting line segment (64), and can opposite rotation direction leave axial stop (86) and turn to the taking-up state, rotatable contact part (72) and back conducting line segment (64) can leave axial stop (86) and taking-up in the body (4) under a kind of state in back; Owing to make it remain on mode of operation on the contact part (72) that sleeve pipe (42) cannot not be overlapped on rotatablely, at first must make on the never rotating contact part of sleeve pipe (42) (72) in the time of therefore not rotatable contact part (72) will being turned to the taking-up state and remove.

6. each electrodusting device is characterized in that in requiring according to aforesaid right,

Ring-type contact device (68) should be provided with, leave charging electrode (20) backward enough distances, when not adopting sleeve pipe (42), counter electrode (52) and preceding conducting line segment (66), do not have on the contact part (72) or back conducting line segment (64) that high-tension electricity cannot not jump to rotatablely from charging electrode (20) with convenient powder spraying apparatus.

7. each electrodusting device is characterized in that in requiring according to aforesaid right,

One cavity (36) is arranged in body (4), wherein be provided with a high pressure generator (32) so that the required high-tension electricity of charging electrode (20) takes place, this high pressure generator can be changed with another high pressure generator; This cavity (36) has an end face (48) that opens wide forward; This high pressure generator (32) is to remain on vertically in the cavity (36) with sleeve pipe (42), at first sleeve pipe (42) must be removed when changing.

8. each electrodusting device is characterized in that in requiring according to aforesaid right,

Body (4) and/or sleeve pipe (42) are made with electrically insulating material.

9. each electrodusting device is characterized in that in requiring according to aforesaid right,

Have can with second sleeve pipe (142) of first sleeve pipe (42) exchange, the difference of this two sleeve pipe (42,142) is, second sleeve pipe (142) have only when be attached on the sleeve pipe (42) rotatable contact part (72) and after conducting line segment (64) all after the powder spraying apparatus taking-up, just can be fastened on the body (4).

10. according to the electrodusting device of claim 9, it is characterized in that,

Second sleeve pipe (142) is made with electrically insulating material.