CN201275597Y

CN201275597Y - Feeding cast form of hollow casting

Info

Publication number: CN201275597Y
Application number: CNU2008201663045U
Authority: CN
Inventors: 苟华强; 肖善龙
Original assignee: ZHEJIANG JIALI WIND POWER TECHNOLOGY Co Ltd
Current assignee: ZHEJIANG JIALI WIND POWER TECHNOLOGY Co Ltd
Priority date: 2008-10-17
Filing date: 2008-10-17
Publication date: 2009-07-22
Anticipated expiration: 2018-10-17

Abstract

The utility model discloses a feeding casting mold for a hollow casting, which belongs to the casting technique. With the prior feeding method, over-proof shrinkage holes are easily formed at the lower part of a casting due to the blocking of feeding channels. The utility model is characterized in that risers are installed at the top of the mold cavity formed by the molding sand in a casting box and at the middle-lower part of the molding sand which forms the hollow cavity of the hollow casting, and are communicated with the mold cavity. When the riser at the top has difficulties in building the unblocked feeding channels in casting, the riser at the middle-lower part can feed the parts where shrinkage holes are caused easily due to the blocking of the feeding channels, thereby ensuring a sound hub casting; reasonable vent channels are further built for the risers so as to increase the capacity of discharging the air in the risers when the risers are fully filled with molten metal, and ensure that when in casting, the pressure of the molten metal in the feeder heads is unblocked, and the casting can be fed smoothly; and when a vent cord is used to built an effective vent channel, the feeding casting mold is capable of supporting the mold sand and avoiding the condition that the sand grains drop into the mold cavity and affect the quality of the casting when in molding.

Description

The feeding casting mold of hollow casting

Technical field

The utility model belongs to placing, especially a kind of method of hollow casting being carried out feeding.

Background technology

It is a general physical phenomenon that object expands with heat and contract with cold, concerning casting, also be like this: melt metal liquid pours into casting mold 91 and (is used in it die cavity casting of molten metal to form the structure of foundry goods with molding sand 2 by what moulding formed in sandbox 1, referring to Fig. 2) afterwards, can shrink along with the reduction of temperature, in order after molten metal solidifies fully, to obtain a foundry goods that perfects that does not have shrink defects, contraction when people adopt and to make one or several cavitys that are called as rising head hold unnecessary molten metal with the compensation casting solidification on casting mold, promptly so-called feeding.If feeding is insufficient, can form a cavity at the position of foundry goods final set, be referred to as shrinkage cavity 5.

Narration for convenience and understanding, can regard rising head as a container that holds excess metal liquid, generally speaking, the material of this container of rising head is identical with the material of casting mold, but in order to improve the feeding efficiency of rising head, people make the rising head container with the heat-insulating property better material, and add chemical material therein.In case molten metal enters in the rising head, these chemical materials will react, and emit heat, make the molten metal temperature in the rising head be higher than the temperature of molten metal in the casting mold for a long time, thereby help feeding, improve feeding efficiency.

When feeding, usually be the top that rising head is arranged on foundry goods, so that the molten metal in the rising head has enough pressure, the resistance of liquid flow when overcoming feeding.

In casting solidification process, because the difference of aspects such as its wall thickness, structure, the setting rate of different parts is inconsistent on the foundry goods, and solidify early at some position, and some position is solidified late.Just in time be at rising head and solidify between the late position that so, the metal liquid stream in the rising head just is blocked to the passage that solidifies late position if solidify position early, it is not smooth that this just is referred to as the feeding passage.Obviously, in order to realize effective feeding, it is necessary keeping the unimpeded of feeding passage.

The wheel hub of hollow casting Large-scale Wind Turbines as shown in Figure 1 is a foundry goods near hollow ball, and about 3 meters of the diameter of spheroid generally has 5 macropores on the spheroid, and wheel hub will carry out nondestructive inspection (NDI), does not allow to exist shrinkage cavity.In order to satisfy this requirement, common way is rising head 4 to be set at the top of wheel hub carry out the feeding (see figure 2).But because the diameter of wheel hub is bigger, the top rising head is just very long to the feeding path of wheel hub bottom, is difficult to guarantee the unimpeded of feeding passage, so, usually forms the shrinkage cavity that exceeds standard in the bottom of wheel hub, and quality can not meet the demands.

The utility model content

The technical assignment of the technical problems to be solved in the utility model and proposition is that to overcome the feeding passage of existing shrinkage compensation method not smooth and easy in the exceed standard defective of shrinkage cavity of the bottom of foundry goods formation, and a kind of feeding casting mold of new hollow casting is provided.For this reason, the utility model adopts following technical proposals:

The feeding casting mold of hollow casting is characterized in that: rising head is all settled in the top of the die cavity that is formed by molding sand in sandbox and the middle and lower part that forms in the molding sand of hollow casting hollow lumen, makes rising head be communicated with die cavity.

As to further the improving and replenishing of technique scheme, the utility model also comprises following additional technical feature, so that be applied to technique scheme when stating technical scheme on the implementation:

The top of described rising head has steam vent, gets rid of the air in the rising head when molten metal is full of rising head when being used to pour into a mould.

The outlet passageway that is communicated with rising head top steam vent is set, so that the molten metal pressure in the rising head is unimpeded and can carry out feeding to foundry goods smoothly when strengthening the ability of getting rid of air in the rising head when molten metal is full of rising head and feeding during cast in the molding sand that forms the hollow casting hollow lumen.

Described outlet passageway is the breather cord that an end places in the steam vent of rising head top, remainder is embedded in molding sand, and this breather cord can be supported molding sand when setting up effective outlet passageway, and sand grains enters die cavity and destroys casting quality when avoiding moulding.

The beneficial effects of the utility model are:

1, settle in the rising head at the top in the molding sand that forms the hollow casting hollow lumen during moulding, rising head is settled in middle and lower part in the molding sand that forms the hollow casting hollow lumen also select location, make rising head be communicated with the die cavity that forms hollow casting, thus when the rising head at top is difficult to set up unimpeded feeding passage when pouring into a mould, rising head by the middle and lower part is not smooth and cause the position of shrinkage cavity to carry out feeding easily to these feeding passages, guarantees to obtain sound wheel hub casts.

2, set up rational outlet passageway for rising head, so as when cast when strengthening the ability of getting rid of air in the rising head when molten metal is full of rising head and feeding the molten metal pressure in the rising head unimpeded and can carry out feeding to foundry goods smoothly; And when setting up effective outlet passageway, can support molding sand with breather cord, sand grains enters die cavity and destroys casting quality when avoiding moulding.

Description of drawings

Fig. 1 is the structural representation of hollow casting (wheel hub).

Fig. 2 is the casting mold structure schematic diagram of existing shrinkage compensation method.

Fig. 3 is the casting mold structure schematic diagram of the utility model shrinkage compensation method.

Among the figure: 1-sandbox, 2-molding sand, 3-die cavity, 4-rising head, 5-shrinkage cavity, 6-outlet passageway, 7-breather cord, 8-foundry goods, the casting mold of the existing shrinkage compensation method of 91-, the casting mold of 92-shrinkage compensation method of the present invention, E-E/K-K-die joint.

The specific embodiment

The technical solution of the utility model is described further with preferred embodiment below in conjunction with accompanying drawing.

As shown in Figure 3, the feeding casting mold of this hollow casting is (wheel hub with the casting large-scale wind power generating set is an example):

Rising head 4 is all settled in the top of the die cavity 3 that 1, is formed by molding sand 2 in sandbox 1 and the middle and lower part that forms in the molding sand of hollow casting 8 hollow lumen, makes rising head 4 be communicated with die cavities 3; The outlet passageway 6 that is communicated with rising head top steam vent is set in the molding sand that forms the hollow casting hollow lumen; This outlet passageway 6 is the breather cord 7 that an end places in the steam vent of rising head top, remainder is embedded in molding sand.

2, the same with existing casting process, carry out mould assembling, cast.

3, after the foundry goods cooling, unpack, knockout, cleaning, remove rising head.

4, carry out finishing, obtain sound wheel hub casts.

According to the wheel hub casts that method of the present utility model obtains, through the ultrasonic examination inspection, do not find shrinkage cavity, quality meets the requirements.

Claims

1, the feeding casting mold of hollow casting is characterized in that: rising head (4) is all settled in the top of the die cavity (3) that is formed by molding sand (2) in sandbox (1) and the middle and lower part that forms in the molding sand of hollow casting (8) hollow lumen, makes rising head (4) be communicated with die cavity (3).

2, the feeding casting mold of hollow casting according to claim 1 is characterized in that the top of described rising head (4) has steam vent.

3, the feeding casting mold of hollow casting according to claim 2 is characterized in that being provided with the outlet passageway (6) that is communicated with rising head top steam vent in the molding sand that forms the hollow casting hollow lumen.

4, the feeding casting mold of hollow casting according to claim 3 is characterized in that described outlet passageway (6) is the breather cord (7) that an end places in the steam vent of rising head top, remainder is embedded in molding sand.