Aluminum Gearbox Housing Production according to Drawings

Aluminum Gearbox Housing Production according to Drawings

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Gearbox housing is kind of die casting parts which require most complicated technology and excellent engineering.The geometry and structure of gearbox are normally complex.In consider of weight and yield rate,most of gearbox housing are made by aluminum die casting,especially for automobile industry.The tooling and precision machining is key for production of gearbox housing.Weiheng metal products have been producing gearbox housing according to customers requirement and drawings over years and had rich experience on tooling design,structure optimization,tight tolerance guaranteed.Please contact us for your requirement.The following example show the production from initial tooling design to final precision machining.

The housing include 3 parts.They are two side plate and one central casing.The most important and difficult parts is central casing.The casting size of central casing is 287x268x79mm,the raw casting is about 3.1kg and average wall thickness is 4mm.The casting size is not small and come with complex geometary.Die filling and multi-sliders are main issue which need take into consideration.

central casing

central casing

central casing

central casing

In addition to the precision required for area the gear and worm shaft and bearing are put,the casting need to be leakage proof under 0.6 bar.The machining surface does not allow any air pores or shrinkage porosity etc.

In according with structure and technical requirement,the parting line were defined.The tooling require four sliders in different direction and the sprue put next to the longest slider.The gate were put onto area where the machining will apply so remaining will be machined off after sprue and gates cut off.

Sprue

Sprue

To make sure the quality of raw casting,the cooling system must be put inside tooling.The tooling life span also affected by cooling system.MAGAMA will be used for analysis of temperature changing during die casting and casting solidification. By analysis,the layout of tooling system will be made with care in order to balance the temperature of whole tooling during die casting production.

In design,each cooling line has flow control switch of its owned.By this way,the tooling temperature can be adjusted by switch on/off separated cooling line.

The mold heat up system put onto mold base.To improve tooling life span and reduce time spent on trial production.The tooling will be heat up before volume production.To achieve this,the heat up system put inside mold base and can make tooling temperature reach 200鈩 in short time,which can improve quality of raw casting and save cost.

Cooling System

Cooling System

The tooling key component include cavity and core and four sliders.Our professional engineer team define the core and cavity and choose proper parting line by NX Unigraphics.The closing area need to be 120-150mm to avoid splash of molten aluminum alloy.The proper draft need to put onto sliders.Some easy broken area need to be made into insert in order to quick change during production.There are three sliders to form the ribs of casting.It will need fine polishing and proper draft,otherwise the soldering problem will happened.

Longest Slider

Longest Slider

One important slider is used for the space where the worm shaft put.The insert need to be used on the slider.It is quite long slider and might be broken or deformed after big volume production.By changing insert,it will save cost of slider remake and improve production efficiency.Four sliders are hydraulic and equipped with movement switch instead of sensor operated.The sensor sliders are more expensive and difficult to do maintenance.

Mold base are used for support die and connected to machine.The mechanical properties need to be concerned while designing mold base.C45 steel is most popular material for mold base.In order to avoid tooling deformation,the mold base size need to meet requirement.One mold base need to bear the pressure of injection and four sliders.Therefore,it need be to 200mm around thickness.

Overflow layout is very important.In designing,most of overflow put on to machining surface and thick area in order to shrinkage porosity and gas porosity accumulated.

Overflow

Overflow

The material compose of main cost of tooling make.H13 is common use and widely accepted material for cavity and core and sliders.The hardness is HRC42-44.Ejectors use SKD61 and the hardness is HRC42-44.Mold base use C45 steel.It will HRC28-32 after hardening and tempering.

The die casting tooling is fundament for production.precision machining is final process for high quality gearbox housing.The whold precision machining process will need three set of 3 axis CNC center.Weiheng metal products equipped with famous brand and can reach tight tolerance and make fast delivery for all customers orders.Face milling are used for contact area which need quite low roughness and high precision for flatness.In order to save machining cost,we decide to do machining for both of contact surface by two 3-axis CNC instead of 4-axis CNC.If much tighter tolerance required,we will consider to 4-axis CNC for machining.Our LITZ MV 1000 4 axis can be workable.Drilling and Tapping will apply on these two side.Both of process were done in CNC in order to get uniform holes and accuracy distance between each holes.The jigs were made according to raw casting before precision machining.We always bear cost of jigs because we understand tooling cost is quite big investment for each customers.

Face Milling

Face Milling

Face Milling

Face Milling

The area where worm shaft and bearing put require boring and burnishing to reach quite tight tolerance and compact and smooth surface finishing.The face milling will apply for the surface which connect to the flanges.The allowance is about 0.3mm in order to save machining cost and avoid air pore.The burnishing were done via our Haas VF2SS because shaft strength and torque can reach requirement of burnishing.The surface roughness after burnising can be Ra0.1-0.2,which is pretty smooth.The boring can be done either by vertical CNC or horizional CNC.If need much deeper borehole,horizional CNC will be more suitable.For 137mm borehole,our LITZ MV 1000 vertical CNC is enough for it.

Boring and Burnishing

Boring and Burnishing

The concentricity need to guarranteed while doing boring since there will be interreference if centricity is not good.The whole depth of boring is 137mm,which require quite nice CNC and boring tools.

Concentricity

Concentricity

The CMM will be next step after machining.The CMM test will be arranged each shift in order to make sure all tolerance meet customers requirement.The test report will be provide customers together with shipment.

CMM

CMM

After CMM test,all gearbox housing will be put onto airthightness tester.Our airtightness tester work ranged upto 12 bar.We will set up fixture which connected to airtightness texter.Our automation engineer is good at making various kind of fixture for tester.By airtightness test,it can avoid extra vaccum impregnation cost for qualified one.All qualified products will be warped by elastic film and put on the pallet and wait for packing into wooden crate.

Airtightness Tester Fixture

Airtightness Tester Fixture

We are professional aluminum die casting manufaturer and all of gearbox housing we produced are exported to europe and north america.Please contact us if you have any inquiries and we will reply within 24 hours

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