阅读说明：本技术 一种涂层机 (Coating machine ) 是由 王俊锋 王�锋 袁明 李�浩 于 2020-05-27 设计创作，主要内容包括：本发明涉及工件涂层技术领域,尤其公开了一种涂层机,包括机箱、设置于机箱的载料机构及涂层机构,载料机构用于承载待涂层的工件,涂层机构将涂层物料涂设在载料机构所承载的工件上；载料机构包括第一架体、转动设置于第一架体的载架、用于驱动载架转动的第一驱动件、转动设置于载架并用于承载工件的第一载具、设置于第一载具的接触轮、设置于载架并用于接触配合接触轮以使得第一载具转动的配合件,涂层机构供应的涂层物料涂设在第一载具所承载的工件上；在工件涂层的过程中,第一驱动件驱动载架使得第一载具所承载的工件公转,借助配合件的对接触轮的抵触配合,实现第一载具带动工件的自转,进而提升工件的涂层良率。(The invention relates to the technical field of workpiece coating, and particularly discloses a coating machine which comprises a case, a material loading mechanism and a coating mechanism, wherein the material loading mechanism and the coating mechanism are arranged on the case; the material loading mechanism comprises a first frame body, a carrier frame rotationally arranged on the first frame body, a first driving piece used for driving the carrier frame to rotate, a first carrier rotationally arranged on the carrier frame and used for bearing a workpiece, a contact wheel arranged on the first carrier, and a matching piece arranged on the carrier frame and used for contacting and matching the contact wheel to enable the first carrier to rotate, and coating materials supplied by the coating mechanism are coated on the workpiece borne by the first carrier; in the process of coating the workpiece, the first driving piece drives the carrier frame to enable the workpiece borne by the first carrier to revolve, and the first carrier drives the workpiece to rotate by means of the interference fit of the matching piece on the contact wheel, so that the coating yield of the workpiece is improved.)

1. A coating machine comprises a case, a loading mechanism and a coating mechanism, wherein the loading mechanism and the coating mechanism are arranged on the case; the method is characterized in that: the material loading mechanism comprises a first frame body, a carrier frame rotatably arranged on the first frame body, a first driving piece used for driving the carrier frame to rotate, a first carrier rotatably arranged on the carrier frame and used for bearing a workpiece, a contact wheel arranged on the first carrier, and a matching piece arranged on the carrier frame and used for contacting and matching the contact wheel to enable the first carrier to rotate, wherein the coating material supplied by the coating mechanism is coated on the workpiece borne by the first carrier.

2. The coating machine of claim 1, wherein: the material loading mechanism further comprises a second frame body arranged on the case, the first driving piece comprises a main shaft piece, a first gear and a first motor, the main shaft piece is rotatably arranged on the second frame body, the first gear is arranged on the main shaft piece, the first motor is used for driving the main shaft piece to rotate, the first frame body is arranged on the main shaft piece, and the carrier frame is provided with a second gear meshed with the first gear.

3. The coating machine of claim 2, wherein: the number of the carrying frames is multiple, the carrying frames are arranged around the main shaft part, second gears of the carrying frames are respectively meshed with the first gears, and each carrying frame is provided with a rotating first carrier; the carrier is provided with a plurality of matching pieces which are respectively in contact fit with the first carriers of the carrier.

4. The coating machine of claim 1, wherein: the carrier is provided with a plurality of first carriers which are arranged along the length direction of the carrier, and the first carriers respectively bear a plurality of workpieces; first support body is equipped with the bracing piece parallel with the carrier frame, and the quantity of fitting piece is a plurality of, and the setting is arranged along the length direction of bracing piece to a plurality of fitting pieces, and a plurality of fitting pieces of bracing piece contact respectively the contact wheel of a plurality of first carriers of cooperation carrier frame.

5. The coating machine of claim 1, wherein: the first carrier comprises a supporting plate sleeved outside the carrier frame and a plurality of carrier heads rotatably arranged on the supporting plate, the plurality of carrier heads are arranged around the rotating axis of the carrier frame, and the plurality of carrier heads respectively carry a plurality of workpieces; the contact wheels are arranged in a plurality of numbers, the contact wheels are respectively arranged on the plurality of carrier heads, and one fitting piece is used for being in contact fit with the contact wheels of all the carrier heads of the same supporting plate.

6. The coating machine of claim 1, wherein: the coating mechanism comprises a first feeding unit, the first feeding unit comprises a first bracket detachably connected with the case and used for bearing a first target, a first heating unit arranged on the first bracket and used for heating and evaporating the first target, a first cooling unit used for cooling the first target borne by the first bracket, and a first magnet arranged on the first bracket and acting on target ions after evaporation of the first target, and the target ions after evaporation of the first target enter the case and are deposited on a workpiece borne by the first carrier to form a coating.

7. The coating machine of claim 6, wherein: the first feeding unit further comprises a second carrier rotatably arranged on the first bracket and a second driving piece for driving the second carrier to rotate, and the second carrier is used for bearing the first target.

8. The coating machine of claim 7, wherein: the second carrier is provided with a first cooling flow channel penetrating through the second carrier, a first target material borne by the second carrier is provided with a target material concave hole communicated with the first cooling flow channel, and the first cooling unit is used for driving external cooling fluid to flow through the first cooling flow channel and the target material concave hole to cool the first target material borne by the second carrier.

9. The coating machine of claim 1, wherein: the coating mechanism comprises a second feeding unit, the second feeding unit comprises a second bracket detachably connected with the case and used for bearing a second target, a second heating unit and a second magnet which are arranged on the second bracket, and a second cooling unit used for cooling the second target borne by the second bracket, the second bracket is provided with a tapered hole used for accommodating the second target and communicated with the case, the aperture of one end, close to the case, of the tapered hole is larger than that of one end, far away from the case, of the tapered hole, the second heating unit is used for heating and evaporating the second target borne by the second bracket, and the second magnet acts on target ions evaporated from the second target; the first target material is a strip-shaped body, and the second target material is a plate-shaped body.

10. The coating machine of claim 9, wherein: the second bracket is provided with a second cooling flow channel, a cooling containing groove communicated with the second cooling flow channel is formed between the second target and the second bracket, and the second cooling unit is used for driving external cooling fluid to flow through the second cooling flow channel and the cooling containing groove to cool the second target carried by the second bracket.

Technical Field

The invention relates to the technical field of workpiece coating, and particularly discloses a coating machine.

Background

In the process of processing a workpiece, a coating is often required to be coated on the workpiece, so that the usability of the workpiece is improved, when the workpiece is actually supported and manufactured, a cutter is one of basic accessories commonly used by various processing equipment, for example, electronic products all need to use a built-in circuit board, a drill point is one of common cutters used for drilling holes in the built-in circuit board, in order to prolong the service life of the cutters such as the drill point, the coating is often required to be coated on the outer side of the cutter, and in the prior art, the cutter is still in the process of coating processing, so that the coating thickness is easily uneven and poor.

Disclosure of Invention

In order to overcome the defects and shortcomings in the prior art, the invention aims to provide a coating machine, wherein a first driving piece drives a carrier frame to enable a workpiece carried by a first carrier to revolve, and the first carrier drives the workpiece to rotate by means of interference fit of a matching piece on a contact wheel, so that the coating yield of the workpiece is improved.

In order to achieve the purpose, the coating machine comprises a case, a loading mechanism and a coating mechanism, wherein the loading mechanism and the coating mechanism are arranged on the case; the material loading mechanism comprises a first frame body, a carrier frame rotatably arranged on the first frame body, a first driving piece used for driving the carrier frame to rotate, a first carrier rotatably arranged on the carrier frame and used for bearing a workpiece, a contact wheel arranged on the first carrier, and a matching piece arranged on the carrier frame and used for contacting and matching the contact wheel to enable the first carrier to rotate, wherein the coating material supplied by the coating mechanism is coated on the workpiece borne by the first carrier.

Further, the material loading mechanism further comprises a second frame body arranged on the case, the first driving piece comprises a main shaft piece rotatably arranged on the second frame body, a first gear arranged on the main shaft piece and a first motor used for driving the main shaft piece to rotate, the first frame body is arranged on the main shaft piece, and the carrying frame is provided with a second gear meshed with the first gear.

Furthermore, the number of the carrying frames is multiple, the carrying frames are arranged around the main shaft part, the second gears of the carrying frames are respectively meshed with the first gears, and each carrying frame is provided with a rotating first carrier; the carrier is provided with a plurality of matching pieces which are respectively in contact fit with the first carriers of the carrier.

Furthermore, the carrier frame is provided with a plurality of first carriers which are arranged along the length direction of the carrier frame, and the first carriers respectively bear a plurality of workpieces; first support body is equipped with the bracing piece parallel with the carrier frame, and the quantity of fitting piece is a plurality of, and the setting is arranged along the length direction of bracing piece to a plurality of fitting pieces, and a plurality of fitting pieces of bracing piece contact respectively the contact wheel of a plurality of first carriers of cooperation carrier frame.

Furthermore, the first carrier comprises a supporting plate sleeved outside the carrier and a plurality of carrier heads rotatably arranged on the supporting plate, the plurality of carrier heads are arranged around the rotating axis of the carrier, and the plurality of carrier heads respectively carry a plurality of workpieces; the contact wheels are arranged in a plurality of numbers, the contact wheels are respectively arranged on the plurality of carrier heads, and one fitting piece is used for being in contact fit with the contact wheels of all the carrier heads of the same supporting plate.

Furthermore, the coating mechanism comprises a first feeding unit, the first feeding unit comprises a first bracket detachably connected with the case and used for bearing a first target, a first heating unit arranged on the first bracket and used for heating and evaporating the first target, a first cooling unit used for cooling the first target borne by the first bracket, and a first magnet arranged on the first bracket and acting on target ions after evaporation of the first target, and the target ions after evaporation of the first target enter the case and are deposited on a workpiece borne by the first carrier to form a coating.

Furthermore, the first feeding unit further comprises a second carrier rotatably disposed on the first bracket and a second driving member for driving the second carrier to rotate, and the second carrier is used for bearing the first target.

Furthermore, the second carrier is provided with a first cooling flow channel penetrating through the second carrier, the first target carried by the second carrier is provided with a target concave hole communicated with the first cooling flow channel, and the first cooling unit is used for driving external cooling fluid to flow through the first cooling flow channel and the target concave hole to cool the first target carried by the second carrier.

Furthermore, the coating mechanism comprises a second feeding unit, the second feeding unit comprises a second bracket detachably connected with the case and used for bearing a second target, a second heating unit and a second magnet which are arranged on the second bracket, and a second cooling unit used for cooling the second target borne by the second bracket, the second bracket is provided with a tapered hole used for accommodating the second target and communicated with the case, the aperture of one end, close to the case, of the tapered hole is larger than that of one end, far away from the case, of the tapered hole, the second heating unit is used for heating and evaporating the second target borne by the second bracket, and the second magnet acts on target ions evaporated from the second target; the first target material is a strip-shaped body, and the second target material is a plate-shaped body.

Furthermore, the second bracket is provided with a second cooling flow channel, a cooling accommodating groove communicated with the second cooling flow channel is formed between the second target and the second bracket, and the second cooling unit is used for driving external cooling fluid to flow through the second cooling flow channel and the cooling accommodating groove to cool the second target carried by the second bracket.

The invention has the beneficial effects that: in the process of coating the workpiece, the workpiece to be coated is firstly installed on the first carrier of the loading mechanism, the first driving piece drives the carrier frame to enable the workpiece borne by the first carrier to revolve, and the first carrier drives the workpiece to rotate by means of the interference fit of the matching piece on the contact wheel, so that the coating yield of the workpiece is improved.

Drawings

FIG. 1 is a schematic perspective view of the present invention;

FIG. 2 is a schematic perspective view of the loading mechanism of the present invention;

FIG. 3 is a schematic perspective view of another perspective view of the loading mechanism of the present invention;

FIG. 4 is a partially enlarged view of portion A of FIG. 2;

FIG. 5 is a schematic perspective view of a first feeding unit according to the present invention;

FIG. 6 is a cross-sectional view of a first feed unit of the present invention;

FIG. 7 is a schematic perspective view of a second feeding unit according to the present invention;

fig. 8 is a sectional view of a second supply unit of the present invention.

The reference numerals include:

1-case 2-loading mechanism 3-coating mechanism

4-accommodating cavity 5-first frame body 6-carrying frame

7-first carrier 8-contact wheel 9-mating piece

11-second frame 12-main shaft element 13-first gear

14-second gear 15-pallet 16-carrier head

17-spacer column 18-first feed unit 19-first carrier

21-first magnet 22-second carrier 23-first target

24-first cooling channel 25-target material concave hole 26-second material supply unit

27-second carriage 28-second magnet 29-second target

31-tapered bore 32-tapered member 33-second cooling channel

34-cooling container 35-vacuum pumping equipment.

Detailed Description

For the understanding of those skilled in the art, the present invention will be further described with reference to the following examples and drawings, which are not intended to limit the present invention.

Referring to fig. 1 to 8, a coating machine of the present invention includes a machine case 1, a loading mechanism 2 and a coating mechanism 3, where the loading mechanism 2 and the coating mechanism 3 are installed on the machine case 1, in this embodiment, the machine case 1 is formed by connecting a plurality of metal plates, the machine case 1 has an accommodating cavity 4, the loading mechanism 2 is located in the accommodating cavity 4 of the machine case 1 and is used for bearing a workpiece (such as a tool) to be coated, and the coating mechanism 3 is used for supplying a coating material so that the coating material is coated on the workpiece borne by the loading mechanism 2 to form a protective coating.

The material loading mechanism 2 comprises a first frame body 5, a carrier frame 6 rotatably arranged on the first frame body 5, a first driving piece for driving the carrier frame 6 to rotate, a first carrier 7 rotatably arranged on the carrier frame 6 and used for loading a workpiece, a contact wheel 8 fixedly arranged on the first carrier 7, and a matching piece 9 arranged on the carrier frame 6 and used for contacting the matching contact wheel 8 so as to enable the first carrier 7 to rotate, when the first driving piece drives the carrier frame 6 to rotate, the carrier frame 6 drives the first carrier 7 to rotate together, and because the matching piece 9 is fixed, when the contact wheel 8 of the first carrier 7 is abutted against the matching piece 9, the first carrier 7 can enable the workpiece connected with the first carrier 7 to rotate relative to the carrier frame 6, and the coating material supplied by the coating mechanism 3 is coated on the workpiece loaded by the first carrier 7.

In the process of coating the workpiece, the workpiece to be coated is firstly installed on the first carrier 7 of the loading mechanism 2, the first driving piece drives the carrier 6 to enable the workpiece borne by the first carrier 7 to revolve, and by means of the interference fit of the matching piece 9 on the contact wheel 8, the first carrier 7 is enabled to drive the workpiece to rotate, and further the coating yield of the workpiece is improved.

The material loading mechanism 2 further comprises a second frame body 11 fixedly arranged in the case 1, the first driving part comprises a main shaft element 12 rotatably arranged on the second frame body 11, a first gear 13 arranged on the main shaft element 12 in an installing mode, and a first motor used for driving the main shaft element 12 to rotate, the first frame body 5 is fixedly arranged on the main shaft element 12, and the carrier frame 6 is provided with a second gear 14 meshed with the first gear 13.

In practical use, the first motor drives the main shaft 12 to drive the first frame 5 to rotate relative to the second frame 11, and the rotating first frame 5 drives the workpiece carried by the first carrier 7 to revolve around the main shaft 12. When the main shaft part 12 rotates, the first gear 13 is driven to rotate together, and by means of the meshing between the first gear 13 and the second gear 14, the rotating first gear 13 can drive the second gear 14 to drive the carrier 6 to rotate, and the rotating carrier 6 drives the workpiece carried by the first carrier 7 to revolve around the carrier 6, so that the rotating effect of the workpiece is further improved, and the coating yield of the workpiece is further improved.

The number of the carrier 6 is multiple, the multiple carriers 6 are arranged around the main shaft element 12, preferably, the multiple carriers 6 are arranged in an annular array around the main shaft element 12, the second gears 14 of the multiple carriers 6 are respectively meshed with the first gears 13, each carrier 6 is provided with a rotating first carrier 7, and the first carriers 7 of the multiple carriers 6 are respectively used for carrying different workpieces; the carrier 6 is provided with a plurality of fitting members 9, and the plurality of fitting members 9 respectively contact and fit the first carriers 7 of the plurality of carriers 6.

In this embodiment, the radius of the first gear 13 is greater than the radius of the second gear 14, and preferably, the radius of the first gear 13 is greater than twice the radius of the second gear 14, so that the slowly rotating first gear 13 can drive the second gear 14 and the carrier 6 to rotate rapidly, thereby improving the rotation effect of the workpiece carried by the first carrier 7 of the carrier 6, and further improving the coating yield of the workpiece.

The carrier 6 is provided with a plurality of first carriers 7, the plurality of first carriers 7 are arranged in a row along the length direction of the carrier 6, and the plurality of first carriers 7 respectively carry a plurality of workpieces. First support body 5 is equipped with the bracing piece parallel with carrier 6, and the quantity of fitting piece 9 is a plurality of, and the setting is arranged along the length direction of bracing piece to a plurality of fitting pieces 9, and a plurality of fitting pieces 9 of bracing piece contact respectively and cooperate the contact wheel 8 of a plurality of first carriers 7 of carrier 6. Therefore, a plurality of first carriers 7 of one carrier 6 can carry a plurality of workpieces at one time, and the coating efficiency of the workpieces is further improved.

In this embodiment, the contact wheel 8 is a first external gear, and the fitting member 9 may be a second external gear engaged with the first external gear according to actual requirements, and the second external gear is fixedly disposed on the carrier 6. Of course, the counterpart 9 may be a sector gear which meshes with the first external gear, in which case the sector gear is fixedly arranged on the carrier 6.

The first carrier 7 includes a supporting plate 15 sleeved outside the carrier 6, and a plurality of carrier heads 16 rotatably disposed on the supporting plate 15, the supporting plate 15 is a substantially circular flat plate, the plurality of carrier heads 16 are disposed around a rotation axis of the carrier 6, preferably, the plurality of carrier heads 16 are disposed in an annular array around the rotation axis of the carrier 6, and the plurality of carrier heads 16 respectively carry a plurality of workpieces, so as to further assist in improving the coating yield of the workpieces. The number of the contact wheels 8 is multiple, the contact wheels 8 are respectively arranged on the carrier heads 16, and one matching piece 9 is used for being matched with the contact wheels 8 of all the carrier heads 16 of the same supporting plate 15 in a contact mode.

Preferably, the supporting plate 15 is fixedly provided with an isolation column 17, when in actual use, the supporting plates 15 of a plurality of first carriers 7 are respectively sleeved outside the carrier 6, the free end of the isolation column 17 is used for abutting against the supporting plate 15 of another first carrier 7, the workpiece carried by the carrier head 16 is positioned between the supporting plates 15 of two adjacent first carriers 7, and the two first carriers 7 are separated by the isolation column 17.

In this embodiment, the isolation pillar 17 is provided with a non-circular hole penetrating through the isolation pillar 17, the carrier 6 is provided with a non-cylindrical column, the non-cylindrical column is accommodated in the non-circular hole, and the inner hole surface of the non-circular hole is used for blocking and abutting against the outer side surface of the non-cylindrical column, so that the first carrier 7 and the non-cylindrical column of the carrier 6 are prevented from rotating relatively and being badly used. According to actual needs, the shape of the non-circular hole can be triangular, elliptical, rectangular, hexagonal and the like, and the cross section of the non-cylinder is matched with the shape of the non-circular hole.

The coating mechanism 3 includes a first feeding unit 18, the first feeding unit 18 includes a first bracket 19 detachably connected to the chassis 1 and configured to carry a first target 23, a first heating unit installed on the first bracket 19 and configured to heat and evaporate the first target 23, a first cooling unit configured to cool the first target 23 carried by the first bracket 19, and a first magnet 21 disposed on the first bracket 19 and acting on target ions evaporated from the first target 23, the target ions evaporated from the first target 23 enter the chassis 1 and are deposited on a workpiece carried by the first carrier 7 to form a coating.

In practical use, the first heating unit of the first feeding unit 18 heats the first target 23, so that target ions formed by heating and evaporating the first target 23 are deposited on a workpiece carried by the first carrier 7 in the accommodating cavity 4 of the case 1 to realize automatic coating treatment, and the first cooling unit is used for cooling the first target 23, so that the first target 23 is prevented from being burst due to overhigh temperature; target ions formed after evaporation of the first target 23 enter the accommodating cavity 4 of the case 1 under the action of Lorentz force in the magnetic field of the first magnet 21 and are accurately deposited on the workpiece, automatic screening of the target ions is realized by means of the difference of the Lorentz force exerted on the target ions and target impurities, and the coating yield of the workpiece is improved.

The first feeding unit 18 further includes a second carrier 22 rotatably disposed on the first bracket 19, and a second driving member for driving the second carrier 22 to rotate, wherein the second carrier 22 is used for carrying a first target 23. During practical use, the first heating unit heats and evaporates the first target 23 carried by the second carrier 22, and the second driving element drives the second carrier 22 to drive the first target 23 to rotate, so that the outer side surface of the first target 23 is uniformly evaporated to form target ions, the uniformity of the target ions supplied by the first target 23 is improved, and the coating yield of a workpiece is improved in an auxiliary manner.

The second carrier 22 is provided with a first cooling flow channel 24 penetrating through the second carrier 22, the first target 23 carried by the second carrier 22 is provided with a target concave hole 25 communicated with the first cooling flow channel 24, and the first cooling unit is used for driving external cooling fluid to flow through the first cooling flow channel 24 and the target concave hole 25 to cool the first target 23 carried by the second carrier 22. The cooling fluid may be cooling water, cooling oil, cooling gas, or the like, according to actual needs, and of course, the first cooling unit is provided with a cooling member for reducing the temperature of the cooling fluid.

In practical use, the cooling fluid delivered by the first cooling unit flows through the first cooling flow channel 24 and the target concave hole 25, and further takes away heat of the first target 23 carried by the second carrier 22, so as to cool the first target 23 and prevent the first target 23 from being cracked due to over-high temperature.

The first magnet 21 is annular, and according to actual needs, the first magnet 21 can be a circular ring or a rectangular ring, and the first magnet 21 is sleeved on the outer side of the second carrier 22. After the first heating unit heats and evaporates the first target 23 carried by the second carrier 22 into target ions, the magnetic field of the first magnet 21 acts on the target ions, so that the target ions move and deflect under the action of lorentz force, and of course, the impurity mixed in the target ions is different from the lorentz force borne by the target ions, so that the target ions are automatically screened, the target ions accurately and stably enter the accommodating cavity 4 of the case 1 to be deposited on a workpiece, and the yield of workpiece coatings is improved.

The coating mechanism 3 comprises a second feeding unit 26, the second feeding unit 26 comprises a second bracket 27 detachably connected with the cabinet 1 and used for bearing a second target 29, a second heating unit and a second magnet 28 which are arranged on the second bracket 27, and a second cooling unit for cooling the second target 29 borne by the second bracket 27, the second bracket 27 is provided with a tapered hole 31 used for containing the second target 29 and communicated with the cabinet 1, the aperture of one end, close to the cabinet 1, of the tapered hole 31 is larger than that of one end, far away from the cabinet 1, of the tapered hole 31, the second heating unit is used for heating and evaporating the second target 29 borne by the second bracket 27, and the second magnet 28 acts on target ions evaporated from the second target 29; the first target 23 is a strip-shaped body, and the second target 29 is a plate-shaped body.

During actual use, the two feeding units respectively heat and evaporate targets in different forms into target ions to enter the accommodating cavity 4 of the case 1, so that the compatibility of the coating machine is improved.

The second bracket 27 is detachably connected with a conical member 32, a conical hole 31 is formed in the conical member 32, the conical hole 31 penetrates through the conical member 32, the conical member 32 is used for pressing and limiting the second target material 29 on the second bracket 27, and the second target material 29 covers an opening of one end, away from the case 1, of the conical hole 31.

The second bracket 27 is provided with a second cooling flow channel 33, a cooling accommodating groove 34 communicated with the second cooling flow channel 33 is formed between the second target 29 and the second bracket 27, and the second cooling unit is used for driving external cooling fluid to flow through the second cooling flow channel 33 and the cooling accommodating groove 34 to cool the second target 29 carried by the second bracket 27. By the arrangement of the cooling container 34, the actual contact area between the cooling fluid and the second target 29 is increased, and the cooling effect of the cooling fluid on the second target 29 is further improved.

The machine case 1 is detachably connected with a vacuumizing device 35, the vacuumizing device 35 is used for vacuumizing the accommodating cavity 4 of the machine case 1, and during actual use, the vacuumizing device 35 carries out vacuumizing treatment on the accommodating cavity 4, so that target ions are deposited on a workpiece in the accommodating cavity 4 in a vacuum environment, and the phenomenon that impurities mixed in air are deposited on the workpiece to cause poor coating of the workpiece is avoided.

The above description is only a preferred embodiment of the present invention, and for those skilled in the art, the present invention should not be limited by the description of the present invention, which should be interpreted as a limitation.