QD8-300.400

Introduction   

QD8 pull type is the technical leader of QD8 series arc spray equipment with advanced technology, reliable quality, convenient operation and high cost performance in the current market. After integrating the advantages and disadvantages of other similar products,we improves the power box, panel, rectification system, electric pile, etc .The improved equipment is beautiful , safer and much more reliable and durable and overcome all disadvantages of the original one.

 

Application   

Arc spray machine is the metal spray equipment which can be used in :

1.Anti corrosion coating of steel structure surface

2. Repair surface defects or processing errors of mechanical parts

3. Preparation of special surfaces for mechanical parts

4. Decorative coatings in iron industry

5 .Quick completion of simple mould by spraying

6. Manufacturing metal powder

Main spraying materials: zinc, aluminum, Pb-Sn alloy, copper, carbon steel, stainless steel and other metals.

According to the production requirements of different working conditions, the spray gun can be fixed on the machine tool to spray regular large work pieces.

 

Main technical parameters and characteristics 

No	Project content	Basic parameters	Remarks
1	Spray gun weight	3kg	Excluding cable and air hose
2	Compressed air  pressure	≧0.6Mpa	flow≧3M3/min
3	Compressed air consumption（M3/min）	(Ф6)1.8 M3/min;( Ф7)2.5 M3/min
4	Spray gun wire feeding tension	≧8kg
5	Spraying efficiency	Zn Wire 21kg/h; Al wire 6.5kg/h	Wire rodФ2； Spraying current200A

 

Spray distance: the distance between the spray gun and the sprayed work piece is within180mm-220mm

Features: especially suitable for long distance and field work

 

  Common spraying materials and selection of spraying voltage and current

 

Spraying material	Diameter	No-load voltage	Spraying current	Air cap selection
Zn、Al、Pb-Sn alloy	Ф1.2－Ф1.3	20V－28 V	50A－80A	Ф5－Ф6
Carbon steel, stainless steel	Ф1.6－Ф2	35 V－40 V	120A－200A	Ф7
copper, Copper alloy	Ф1.3－Ф2	35 V－40 V	100A－200A	Ф6－Ф7
Zn、Al、Pb  alloy,Al  alloy	Ф2	22 V－28 V	150A－200A	Ф7
Ni-Al Alloy wire	Ф2	35 V－40 V	150A－200A	Ф7

 

 

 

Features: compared with others , the arc spraying machines one has the following features:

1.Vertical frame structure, reasonable air inlet and outlet channels and components layout

2.The control system adopts high-quality electrical components which makes the operation more reliable and the manufacturing process of power supply more reasonable

3 .The system has overload and short circuit protection

4.The diameter of the rear wheel of arc spray power supply is usually 200 mm , and the diameter of the rear wheel of this power supply is 250 mm which is convenient for climbing over obstacles on the construction site.

5.In addition to the wire feeding voltmeter, the wire feeding ammeter is also added. Through the wire feeding voltmeter, the spraying current can be preset. During the spraying process, the wire feeding ammeter is used to check whether the mechanical and electrical conditions of the spray gun are in good condition.

6.The output of the DC high current part is semi concealed type, the fixed screw can be m8-m12mm, and the cable connector is flat type contact so as to avoid the insulation board burning due to the hair heat of the output electric pile, and the output electric pile head will not be damaged due to the heat of the cable connector. The connection circuit of low voltage and high current inside the power supply is coated with conductive paste instead of tinning process.

7.Suitable for pull type arc gun

8 .The power supply integrates working condition control of spray gun, wire feeding speed regulation and gas pipeline, and is an ideal special equipment for arc spraying.

9.The control and operation are very simple as long as you toggle the small switch at the bottom of the spray gun and the remote control realized.

 

Main structure of the spray gun(Picture 1） 

1.Nozzle assembly is an independent unit assembly collecting gas and electricity which consists of the following main components.

A .Arc light cover which is used to shield the arc light does not irradiate the operator within 130 °

B .Front conduit assembly: it is made of wear-resistant material with good conductivity. It plays a guiding role in forcing two wires to cross, and it is also one of wear replacement parts. In general, only copper parts (connection nozzles) at the end of the conduit can be replaced.

C .The adjusting air cap is made of ceramic material, and its outer diameter is M39 × 1.5 thread, which can be adjusted freely in axial direction. Generally, the distance from the intersection of the second line to the plane of the air cap is 1-3 mm. If the intersection of the second line is in the air cap, there will be detonation and "coating accumulation". If the intersection of the second line is far away from the plane of the air cap, there will be coarser coating particles. (therefore, the adjustment principle is: when adjusting the distance from the air cap plane to the intersection of the second line, the closer the air cap plane to the intersection of the second line is, the better the distance without explosion.)

2.Wire feeding power mechanism: the wire feeding power is to drive a group of planetary systems by using a DC micro motor, and then through a pair of screws and worm gears to a pair of wire feeding rollers, so that the metal wire is continuously delivered to the front of the nozzle, and the wire feeding speed is regulated by the electronic circuit stepless.

3 .Wire clamping mechanism: turn the tightening button to ensure the proper pressure of the wire feeding roller so that the wire can be delivered to the front of the nozzle at a constant speed.

 

Electrical equipment 

Figure 3 shows the relationship between arc spray power and supporting equipment

 

Figure 2 shows the working principle schematic diagram of arc spray power

 

4、Pull gun connection

a、 Figure 5 shows the connection diagram of the control line of the pull type spray gun

 

b、Speed regulation principle

Figure 6 shows the principle of wire feeding speed regulation of spray gun

 

The protective measures of the sprayer are as follows：(according to electrical schematic diagram) 

Power switch QF is also used for short circuit protection of equipment, fuse FU1 and FU2 work as control part, fan motor used as short circuit protection.FU3 is used for spraying control and short-circuit protection of indicator light, FU4 is used as short-circuit protection of wire feeding speed regulating circuit while FU5 is used for short-circuit protection of control circuit.

The thermal relay FT is used as the overload protection of the main transformer. In case of overload, DC output is stopped for the protection device when "overload" indicator H1 is on.

The spray machine is suitable for the pull type arc spray gun produced by our factory. Wiring and control are on the power panel.

The "remote control, near control" switch S4 on the panel is a specially selected switch for the remote control of the spray gun. The switch is turned to the top (near control), and the spraying operation is controlled by the "spraying, stopping, wire feeding" switch S3 on the power panel; the switch S4 is turned to the bottom (remote control), and the remote control is realized.

 

Connection of the device 

Figure 7 for the connection of pull type arc gun

 

 

Figure 7 shows the connection diagram of air hose, cable and control cable on the equipment. If you want remote control, you need to lengthen the cable, air hose and control cable.

 

 

Operation steps and key points 

1. Turn on the air compressor, keep the air pressure above 0.6MPa (not less than 0.5MPa when spraying), turn on the power switch, and the "power on" indicator light H2 is on.

2. Make sure that the spraying material is not penetrated on the arc spray gun when selecting the spraying voltage.Turn the "remote control, near control" switch S4 to the "near control" position on the panel, and turn the "spraying, stop, wire feeding" switch to the "spraying" position.The red indicator light "air on, electricity on, wire feeding" on the power panel lights up one by one at that time and compressed air is ejected from the spray gun. About 2 seconds later,there is a voltage indication on the "spraying voltage" meter . At this time, the spraying voltage can be set to the required voltage through the "voltage coarse adjustment, voltage fine adjustment" switch. (This voltage is determined according to the spraying material. Once set, it is unnecessary to set it again during spraying.)

3.Turn the "spray, stop, wire feed" switch S3 to the "stop" position, take the wire to be sprayed and send it to the wire feed wheel until there is a little air cap hole through the head of the spray gun, align with the groove of the pressure wheel and press tightly with a certain pressure. (The soft metal wire can be pressed until it can not be pulled)

4.Adjustment of spraying current: turn the "spraying, stop, wire feeding" switch S3 on the panel to the "spraying" position. At this time, compressed air is ejected from the spray gun.,The red indicator light on the panel is fully lit after 3 or 4 seconds then press the wire feeding switch (black) in the middle of the spray gun handle, finally sparks will be ejected from the spray gun. At this time, adjust the "wire feeding speed regulation" knob on the panel, and look at the "spraying current" Table, adjust the spraying current within the range of 150A-180A.

5.Release the wire feeding switch in the middle of the spray gun handle, stop spraying and turn the "remote control, near control" switch S4 to the "remote control" position meanwhile only the "power on" indicator light on the panel is on. No compressed air is ejected from the spray gun and the spraying equipment is on standby. (If compressed air is still ejected from the spray gun please pull the small switch at the bottom of the spray gun handle to stop spraying.)

6.Pull the small switch at the bottom of the spray gun handle and the red indicator light "air on, electricity on, wire feeding" on the panel will light up in turn. Compressed air will be ejected from the spray gun. After the red indicator lights are all lit up, press the wire feeding switch in the middle of the spray gun handle, and the spray gun will have sparks ejected, and the spray can be normal. When closing the gun, release the wire feed switch in the middle of the handle and pull the small switch at the bottom of the handle. Only the "power on" indicator light is on the power panel, and the power supply is restored to the power on standby state. Repeat step "6" to turn on and off the spraying power supply and spray normally

Notice :Compressed air is ejected from the spray gun, and there is direct current on the two cables and the spray gun stake!!!

Two metal wires at the back of the spray gun must not touch each other or touch a metal object at the same time to prevent short circuit during spraying.The wire for spraying shall be clean, smooth and oxide free

 

Equipment maintenance and precautions 

The routine maintenance of arc spraying system is very important. Due to pollution and metal dust accumulation, it will produce wear and reduce the insulation strength and shorten the service life of the equipment. Therefore, the metal dust and dirt on the spray gun should be cleaned every shift. In addition, the following points should be noted.

1.The sprayer shall be placed in a place with small temperature difference, less dust, flat floor and dry ventilation and shall be protected from the sun, rain and small animals. Dust cover should be used when not in use.

2.Requirements for application range: the ambient temperature is from 10 ℃ below zero to 40 ℃ above zero, and the altitude is not more than 1500m.

3. It is strictly prohibited to shift gears when spraying. The DC output and cable joint shall be fixed firmly without looseness.

4.During the spraying operation, especially large current output occurs the voltage drop will be about 10%. This is a normal phenomenon, not a fault of the machine.

5.The short distance (within 10m) of AC power supply incoming line shall not be less than 4mm2, and when it is more than 10m, the incoming line shall not be less than 6 square millimetre.

6.Equipment grounding, power incoming line and cable insulation should be kept in good condition.

7.If any fault is found, it should be eliminated in time meanwhile changing the control and protection circuits is forbidden.

8.Turn on the main power switch and the fan should work normally. If not, cut off the power switch, otherwise the rectifier diode will be burnt out.

9.Pay attention to the wind direction during spraying procession and make sure that the equipment and people are in the upwind position.

10.Connect and unplug the four core connector for spray gun wire feeding, as shown in Figure 8. Align the slot position when connecting, do not push or pull to rotate so as to avoid damage.

11.If compressed air is ejected from the spray gun mouth, the two cables must have direct current. Please do not repair the spray gun at this time.

12.When repairing spray gun or setting wire feeding voltage, please turn "spray gun working condition" switch S3 to "wire feeding".

13.The nozzle mouth should be checked after each installation of the spray gun. If two wires do not intersect well, it will be unfavorable for arc starting and unstable spraying.

14.During spraying procession, two wires must not collide behind the spray gun.

15.Clean regularly, use brush and dry compressed air to remove the dust on the components in the power box. If the environment is not good, please shorten the cleaning cycle.

16.The qualified electrical personnel should be invited for the maintenance of the equipment and the power supply should be cut off for the maintenance.

 

Figure 8 Connect and unplug the four core connector for spray gun wire feeding

 QD8-300/400 Arc spray machine 

Packing List
D8-300 Arc spray machine			QD8-400Arc spray machine
No	Name of the product	Quantity	No	Name of the product	Quantity
1	QD8-300 Arc power supply	1 piece	1	QD8-400Arc power supply	1 piece
2	Electric spray gun	1 bunch	2	Electric spray gun	1 bunch
3	70 cable（10meters）	2 pieces	3	702cable（10meters）	2 pieces
4	10 meter air hose	2 pieces	4	10 meter air hose	2 pieces
5	Control line 10meter	1 piece	5	Control line 10meter	1 piece
6	Protective hose	1 pair	6	Protective hose	1 pair
7	Vulnerable parts of electric gun	1packet	7	Vulnerable parts of electric gun	1packet
List of vulnerable parts	Upper and lower wire feeding wheels	1 pair	List of vulnerable parts	Upper and lower wire feeding wheels	11 pair
	Handle switch	1piece		Handle switch	1piece
	Carbon brush	1 pair		Carbon brush	1 pair
	Brush air cap	2 pieces		Brush air cap	2 pieces
	Insulating gasket	8 pieces		Insulating gasket	8 pieces
	Connecting nozzle	4 pieces		Connecting nozzle	4 pieces
	Anterior catheter	2 pieces		Anterior catheter	2 pieces

Arc spraying technology is a rising thermal spray technology in the1980s which is widely used in many sectors and industries.It becomes one of the most important technologies in the current thermal spray industry.

The principle of arc spraying is that two metal wires are respectively connected with the positive and negative stages of the power supply to generate high temperature when they are in contact which makes the end face of the metal wire melt and then the molten metal is atomized with compressed air to spray on the surface of the work piece at a high speed to form a coating.

 The QD8-300 (400) Arc spraying machine produced by our factory is improved and manufactured on the basis of the pull type electric arc spray machine designed by TOFA Corporation of the United States. The advantages is strong coating combination, high spray efficiency, low energy consumption, less material loss, simple and convenient operation, and high safety and reliability of the equipment.