die casting how it works in china die casting suppliers foundry

Die casting may be classified as a permanent mold casting system in die casting and foundry; however, it differs from the process that the molten metal is forced into the mold or die under high (1000 to 30,000psi;6.89 to 206.8MPa) pressure during die casting process in die casting foundry.

during die casting process,the  die casting material solidifies rapidly( within a fraction of a second) because the die is water cooled. Upon solidification. the die is opened and ejector pins automatically knock the castings out of the die.

most of the castings will have die casting flash where the two die halves come together. This is usually removed in a trimming die, but may be done with the aid of abrasive belts or wheels or by tumbling now in china die casting suppliers foundryies.

if the parts are small. several of them may be made at one time in that is termed a multicavity die.

two main types of die casting machines are used: the hot chamber and the cold chamber types.

hot chamber die casting:

the hot chamber die casting machine is shown following picture. the material is kept in a heated holding pot. as the plunger descends. the required amount of alloy is automatically forced into the die. as the pistion retracts. the cylinder is again filled with the right amount of molten metal.an integrap feeding system makes the hot chamber die casting machine easy to automate. recent improvements in design make the machines particularly advantageous for magnesium parts in china die casting factories.


















cold chamber die casting:

this process gets its name from the fact that the metal is ladled into the cold chamber for each shot. this procedure is necessary to keep the moltenmetal contact time with the steel cylinder to a minimum. this process is used for copper based metals and aluminum.

advantages and limitations of die casting process:

die casting machines can produce large quantities of parts with closed tolerance and smooth surfaces. the size is only limited by the capacity of the machine. most die castings are limited to about 75lb(34kg)zinc, 65lb(30kg)aluminum. and 44lb(20kg) of magnesim. die casting companies in china can make all range of such types of die castings.

die casting in china can provide thinner sections than any other casting process. wall thickness as thin as 0.015in (0.38mm) can be achieved with aluminum in small items.

however a more common range for large sizes will be 0.015 to 0.18in(2.67 to 4.5mm) that die casting foundry china can make.

some difficulty is experienced in getting sound castings in the larger capacities for die casting factory  have face to. Gases tend to be entrapped. which results in low strength and annoying leaks. one way to reduce metal sections without sacrificing strength is to design in ribs and bosses.

anothers approach to the porosity problem has been to operate the machine under a vacuum. this process is now being developed in china die casting suppliers factory.

the surface quality is dependent on that of the mold. parts made from new or repolished dies may have a surface roughness of 24uin, the hight surface finish available means that. in most cases, coating such as chrome plating. anodizing and painting may be applied directly.

more recently,decorative finishes of texture as obtained by photoetching have been applied. the technique as been used to simulate woodgrain finishes. as well as textile and leather finsihes, and to obtain checking and crosshatching take by die casting companies in china.

the initial cost of both the die casting machine and the dies limits this process to relatively high production quantities. the die costs are high because of the high accuracy with which they must be made and the high polish required to the surface.

perhaps the sharpest restriction on the die casting process comes from the limited range of materials that can be cast,that is, zinc-, aluminum- .magnesiom-, and copper-based allys, recently, some progress have been made with ferrous materials in china die casting suppliers foundry.

following pictures show DLFT one of china die casting suppliers exporting OEM aluminum die casting fire hose reel frame made according to importer drawing.

dei casting mould

dei casting mould

dei casting mould 2

dei casting mould 2

dei casting mould 3

dei casting mould 3

die casting reel frame

die casting reel frame

die casting reel frames

die casting reel frames


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the layout and main casting of automobile parts

The automobile industry is a fast developing industry. from the later 18th century when the first automobile was put on road. this industry has developed tremendously.

now there are thousands of factories all over the world manufacturing numerous types of automobiles. This industry employs millions of men and women directly in allied industies.

and automobile castings industry developing very fast along with the automobile industry fast developing,automotive casting manufacturers china and india have growed up along with they exporting OEM automobile casting parts such as  various automobile casting components, automobile die casting parts,car body casting,car engine casting parts,automobile engine cover castings,auto generator part castings,auto turbo part castings,automobile gearbox die castings,automobile charge air cooler tank castings,auto lighting components die casting and auto wheel hubs castings,automobile brake disc castings ,automobile water body casting, and  automoblie shock absorber inertia ring castings to USA,EUROPE AND JAPAN according to importers' drawings and request.

Now car engine casting process have also develop quickly in china automobile casting industry these years.

The automobile industry is a developing and demanding industry which does not find its end or saturation point. there is a great demand for trained and experienced persons in this industry for automobile castings, die casting automobile parts, system componets,auto Brake system castings foundryman job and machining works.

An automobile probably has about 700 different parts in it. some of them make by grey iron  sand castings, but most of them  made from alumimum die castings.

the layout of a car shows the posion of the main parts of an automobile. it consist of engine located at the front of the vehicle, followed by a clutch, gear box,propeller shaft, universal joint,differential, back axle etc.

the radiator is located in front of the engine, various others parts of the vehilce shown in the layout are dynamo, horn, steering box, fan, carburettor, air filter, steering wheel, cylinder, petrol tank, rear axle, front axle.

the drive from the gearbox is conveyed through a short shaft to the front universal joint of the propeller shaft. from the propeller shaft it is conveyed to the rear universal joint through a sliding splined type of joint.

the bevel gear of the short shaft is driven by the rear universaljoint. the bevel gear meshes with a large bevel gear which drive the two rear shaft through a differential gear.

for controlling the movement of the vehicles or to stop them, efficent braking system is a necessity for a vehicle. brakes attached to each of the four types. in the initial type, a pair of shoes carried on a stationary plate is expanded in contact with a wheel rotating drum mounted on the wheels to arrest the motion of the drum.

in the modern type of brakes, one or more pairs of pads are carried in a caliper attaced to the axle or wheel supporting linkage.

the side of the disk mounted on th wheel are griped by these pads, by applying pressure on a pedal, the brakes are applied. a hand lever acting through a separate linkage and locked in the one position is used.

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electric motor components diagram

For better understanding of a whole electric motor, no matter it's dc electric motor components or ac electric motor components,it is quite necessary to have some idea about the operation or purpose of electric motor components. no matter these motor components supplied by electric motor components manufacturersor electric motor components suppliers in china or from india.

each components or unit has its own special functions to perform and in conjuction with the other electric motor component constitutes a electric motor. those who want to operate, repair or assemble elctric motor must be able to recoginize different basic electric motor components by sight and know what their particular functions are.

With different number and arrangement of electric motor main components.electric motor vary in their outer appearance and size as well as in the details of construction. However, they all have the same main electric motor component parts which, though the components parts may look different. will perform the same functions.

By parts each electric motor can be separated into fixed parts and moving parts.

Roughly speaking, fixed parts component of electric motor refer to the motor frame which rests on a hull structure termed as electric motor foundation or motor seat,motor frame, motor end cover.etc.

While moving parts component in electric motor include motor rotor, motor shaft,bearing,motor fan. etc.

the following is a electric motor components diagram brief introduction on the basic electric motor components:

1.motor frame

cast iron motor frame, material standard subjected to different forces such as inertia and impact of the moving parts apart from supporting the whole weight of electric motors.  by centrifugal casting electric motor such as cast iron motor casing,cast iron motor body,electric motor body casting material according to ASTM, DIN,BS standard.

2.motor end cover

electric motor have two cast iron end covers,and is mounted up on the motor fame two side,as support of motor shaft,electric motor body part casting material usually is grey iron casting.

electric motor components diagram

electric motor components diagram


















3. motor shaft

the motor shaft turns under the action of rotor. the shaft supported by two side bearing which mounted on the two end cover. the shaft output turning throught the shaft outside of motor frame.so that to turn others  equipment like pump or others turning.

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how many valve types manufacted by valve suppliers china

many valve types manufacted by valve suppliers china, valve components suppliers and valve accessories suppliers in china.

1. valve definition by valve techologies organizaton:

 Valves control or interrupt flow. Basically, they have bodies furnished with flanged or screwed ends (or ends prepared for welding) for connection to the joining pipes and internal passages arranged so that they can be restricted or closed, this is done,  in valves,by lowering, raising or rotating a disc in relation to a seating surface or by controlling the movement of a ball.

2. valve types that china valve manufacturers can make.
the most commonly used valves fall into the following categories:globe valves, gate valves, butterfly valves, check and non-return valves and control valves. all these types valve can be manufactured by valve suppliers china.

3.The globe valve has a bulbous body, housing a valve seat and screw down plug or disc arranged at right angles to the axis of the pipe. china valve components suppliers export lot of such kind of valve components castings abroad every year.

4.Unlike the globe valve,gate valves give full bore flow without change of direction. a gate can be moved in a direction at right angles to the flow by ascrewed spindle working in a nut.valve accessories suppliers in china made OEM such kind of valve parts according to importers' drawings.

5.A check valve is another name for a non-return valve, it allows flow in one direction only.

6. A relief valve can be used to ease excess pressure.lt consists of a disc held closed by a spring-loaded stem. the compression on the spring can be adjusted so that  the valve opens at the desired pressure.

Usually valve and fittings fitted in engine rooms,boiler rooms,pump rooms and shaft tunels are to be easily_accessible for operation.Where the valves and fittings are situated under the floor plate.not easily accessible for operation, they are to be provided with extended operating_rods or tools for operation.

Furthermore holes are to be cut in the floor plate under which the valves or fittings are located and to be provided with covers.

hope valve world 2016 can have a good year.

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what is centrifugal pumps

 centrifugal pumps unlike the reciprocating displacement pump. the simple centrifugal pump, which does not have a positive suction action,consists of a rotating impeller within a stationary pump casing.The fully shrouded.single entry impeller is the type most widely used.

The impeller is mounted on a shaft driven by a prime mover.it consist of a number of vanes backward from the direction of the rotation between the shrouding.

Water enters the rotating impeller through the entry,known as 'eye',at the centre. Due to the circular motion given it is thrown hy certrifugal force to the open periphery of the impeller where it leaves tangentially and enters the space in the casing.and then directed to the outlet branch.

Centrifugal pumps are non-positive and fairly low pressure units. Here a closed discharge valve.will not cause excessive pressure to build up.

centrifugal pumps can be divided into volute, diffuser, mixed-flow, axial flow and turbine or regenerative types.

centrifugal pumps find their widest application for dealing with large volumes with medium-to-low heads and Viscositis.Centrifugal or radial flow pumps give regular delivery,and are quiet in operation.

Axial-flow and semi-axial-flow rotary pumps are frequenLly used for large volumes and low heads,as they are simple.occupy little space and are low in capital cost.

Vertical pumps are in general use.because floor space is usually more valuable than height in engine rooms.

 Centrifugal units require to be primed if the liquid level is below the pump. Small integral reciprocating displacement priming pumps are sometimes provided,hut there is a wider use of water-ring pumps for priming purposes, because of their simplicity.

Various other means. such as internal recirculation,steam ejectors,etc. are also used in appropriate cases. 

In general. reciprocating pumps are suitable for delivering small quantities at high pressure, rotary pumps are used for moderate quantities at moderate pressure,and centrifugal pumps are more suitahle for large quantities at low pressure.

Centrifugal pumps,however,can he designed with a number of impellers in series to attain a high final delivery pressure. They are popular because they are very simple.

in construction,and can produce smooth,constant,non-pulsating discharge.

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what is marine positive displacement pump

A pumps  is a device which adds the energy to a liquid or gas,causing an increase in its pressure and perhaps a movement of the fluid.

A basic pumping system consists of a suction branch, a pump and a discharge branch. the pumps employed on board ship fall into two broad classes:positive displacement pumps and centrifugal pumps.

positive displacement pumps  are those where the volume of the pump chamber is alternately increased to draw the liquid in from the suction pipe and then decreased to force the liquid out into the delivery pipe.

the liquid or gas is displaced from the suction to the discharge by the mechanical variation of the volume of a chamber or chambers.

This kind of pumps can be subdivided into two main clawes: reciprocating pumps.in which a plunger or piston is mechanically reciprocated in a liquid cylinder.

And rotary pumps,where the liquid is fored through the pump cylinder or casing by means of screws or gears.under reciprocating are the direct acting,power, and crank-fly- wheel types.

while under rotary are the gear, Vane,screw and piston types. Reciprocating and rotary positive displacememt pumps are self-priming,and can deal with liquid from a level below the pump.

The typical pumps employed in steering gear hydraulic system are rotary-piston pumps,classified either axial or radial type. The pistons in an axial pump operate along the axis of the pump drive shaft.

The cylinder block has a series of cylinder bores with pistons that move in and out.As the block rotates. each piston moves in and out of its cylinder, the length of stroke depending on the angle of the cylinder block with reference to the drive plate or swash plate according to the designs.

As each piston moves outward.oil is drawn into the cylinder bore through the valve plate.On the return stoke,the oil is forced out through the valve plate under pressure.

gear pump is a represent of the rotary pump family and is commonly used on hoard a ship.it consists of two or more meshing gears(spur,single or double helical teeth) enclosed in a close-fitted housing. these are used extensivelv for pumping fuel oil. lubricating oil and hydraulic oil.

When gears are unmeshed on the inlet side. a pressure drop occurs that helps the atmospheric pressure acting on the surface of the oil in the reservoir to force it up the pipe to fill the void,the oil is then transferred around the periphery of the pump housing.

As the gear teeth mesh again on the outlet side,they form a seal that prevents oil from backing up to the inlet, the oil in the void is then be forced out into the discharge line.

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iron casting foundry finishing operations in china

iron casting foundry finishing operations in china usually take following  steps:

After iron casting process, the castings have solidified and cooled somewhat, iron casting foundry take those castings and place on a shakeout table or grating on which the sand mold is broken up, leaving the iron casting free to be picked out.

The iron casting is then taken to the finishing room where the gates and risers are removed.

Small gates and risers may be broken off with a hammer if the iron casting  material is brittle such as in grey iron casting process. Large iron casting require sawing, cutting with a torch, or shearing.

Unwanted metal protrusions such as fins, bosses, and small protions of gates and risers need to be smoothed off to blend with the surface.

Most of this work is done with a heavy-duty grinder and the process is known as snagginh or snag grinding.

On large iron casting it is easier to move the grinder than the work, so swing-type grinders are used.

Smaller iron casting are brought to stand or bench type grinders. hand and pneumatice chisels are used to trim castings or with others iron casting equipment used in china iron casting foundry

A more recent method of removing excess metal from ferrous castings is with a carbon air torch. This consists of a carbon rod and high amperage current with a stream of compressed air blowing at the base of it. 

This oxidizes and removes the metal as soon as it is molten. in many iron casting foundry in china, this method has replaced nearly all chipping and grinding operations. these step use by many  iron casting suppliers in china

This is the iron casting in china situation.  there are many iron casting manufacturers all around china mainland. every year produce lots of  iron casting products and export to all over the world by china iron casting suppliers . quality excellent, price competitive. but this have caused china heavy air polluted.

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fire fighting equipment play key role in a big fire

Firemen had been fighting the forest fire with many fire hydrants around and fire hoses,fire water pumps and fire fighting helicopter for nearly three weeks before they could get it under control.

A short time before. great trees had covered the countryside for miles decorated with red colored fire hydrants around the green grass and forest.

Now, smoke still rise up from the warm ground over the desilated hills. and those fire hydrants which had play key role in the big fire fighting still stand around there,but some of these fire hydrant broken because of big fire burned.  thanks for these fire hydrants, fire hose and fire fighting water pump which supplied enough water for pulling down the big fire.

winter was coming on and the hills threatened the surronding villages with destruction. for heavy rain would not only wash away the soil but would cause serious floods as well. in case have floods. the fire water pump and fire fighting equipment can also play key role to pump  the flood water outof the villages.

When the fire had at last been put out by firemen with fire hydrant, fire hose, fire water pump ,fire fight equipment helping. the forest authorities ordered 1000 set of a new fire hydrants and  fire hydrant parts from fire hydrant valve manufacturers in china.  thses new fire hydrant will be replaced those fire hydrant broken because of hte big fire, and  fire hydrant parts which would use to fire hydrant repair which was slightly broken in this fire.

And the forest authorities also ordered also some grass seed  which was sprayed over the ground in huge quantities by areoplanes, the planes had been planting seed for nearly a month, and use fire hydrants around there and fire pump to make rain to water the grass seed, by the spring time come on, however in many places the grass had already taken root. in place of the great trees which had been growing there for centuries. patches of green had begun to appear in the blackened soil.so you can see the fire fighting equipment play realy very important key role in a big fire


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pump casting process used in china pump casting foundry

pump casting foundry in china, there is much more to casting than selecting a process and making the appropriate pattern in pump casting process in china. During the past two decade since china entry into WTO.  China pump castings suppliers  manufacturers research and production experiences have provided scientific principles for better pump casting techniques.

For china pump casting foundry, the important considerations are the rate at which a pump casting mold cavity is filled, pump casting gate placement, pump casting riser design, the use of chill block of pump casting, and padding in pump casting process.

Filling the pump castings mold cavity. The velocity with which the molten metal fills the pump casting mold is determinded by the cross-sectional area of the gating system and mold-puring rate is the key factory for pump casting foundry foundrymanship.

Too slow a mold pouring rate means solidification before filling some parts of the mold. Allowing surface oxidation. Too high a pouring rate caused by too large gating system causes sand inclusion by erosion, particularly in green sand pump casting molding, and turbulence. These two all easy to cause pump casting defects

The minimum cross section in the gating system is called a choke. In the strict sense. The choke is the section in the gating system, when the gate system is choked at the bottom of the sprue.

It is called a nonpressurized system. This system is somewhat less reliable than a pressuried in which the choke is at the gate of pump casting molding system.

The first metal in the pouring basin and down the sprue usually has some turbulence that carries slag into the runner.To avoid slag in the pump castings, pump casting specialists suggested that the runner should extend past the last gate to trap the initial slag.

By the time the gates become operative. The liquid level should be high enough so that no slag can enter the pump casting cavity.

The runner should be laid out to minimize turbulence. That is it should be as straight and as smooth as possible. The gate is made to enter the cavity at the parting line of the pump casting mould.

pump casting specialists arrange gating may also be made at the top or bottom of the cavity. The parting lines gate is the easiest for the pump casting pattern maker to make;

However, the metal drops into the cavity, which may cause some erosion of the sand and some turbulence of the metal and finally cause for example like pump impeller casting defects

etc. For nonferrous metals, this drop aggravates the dross and entraps air in the metal of pump castings.

Top-gating is used for simple pump casting parts in gray iron, but not for nonferrous alloys pump casting materials, since excessive dross would be formed by the agitation.

Bottom gating provides a smooth flow of metal in the pump casting mold, however. If does have the disadvantage of an unfavorable temperature gradient. It cools as it rises, resulting in cold metal in the riser and hot metal at the gate.

Risers are designed by pump casting specialists and placed so as to ensure filling the cavity during solidification. They also act to relieve gas pressure in the pump casting mold and to reduce pressure on the lifting surface of the pump casting mold in china pump casting foundry

The volume of metal in the riser should be sufficient to retain heat long enough to feed the shrinkage cavity and to equalize the temperature in the pump body casting mold, avoiding casting strains.

The raiser requirements vary with the type of pump casting materials being poured. Gray cast iron pump casting parts, for example, needs less feeding than some alloys because a period of graphitization occurs during the final stages of solidification. Which cause an expansion that tends to counteract the metal shrinkage.

Many nonferrous metal pump casting part require elaborate feeding systems to obtain sound pump casting. The feed metal must be located above the highest point of the casting.

Chill Blocks are metal blocks placed in the pump body casting mold for localized heat dissipation. They may be placed at an intersection or joint where there is a comparatively large volume of metal to cool. thus relieving a hot spot or maintaining a more uniform cooling rate and better microstructure.

They may also be placed at the far surface of a pump body casting mold. Away from a riser or sprue. This will help the far end of the mold to freezed rapidly. Promoting directional solidification.

Chill blocks are also used by pump casting foundry at points where it is desirable to have localized hardening, as in the case of pump impeller casting process or pump bowl casting process.

Padding consists of adding to or building up a section to obtain adequate feeding of isolated section like some pump body casting and pump bowl casting, to feed central or outside boss of the pump body casting or pump bowl casting.

Can use risers with padding. Can provided a yield of say 45% of the metal poured. By the rule of thumb. The total thickness of pad and casting should not be less than one fifth of the metal feeding distance. This rule is not absolute but a good generalization in pump casting process.

pump casting process

pump casting process

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本文链接地址: pump casting process used in china pump casting foundry