CN216801593U

CN216801593U - Gas generator cylinder cover and sand mold thereof

Info

Publication number: CN216801593U
Application number: CN202220092138.9U
Authority: CN
Inventors: 李宏兴
Original assignee: Henan Xurui Alloy New Material Manufacturing Co ltd
Current assignee: Henan Xurui Alloy New Material Manufacturing Co ltd
Priority date: 2022-01-14
Filing date: 2022-01-14
Publication date: 2022-06-24
Anticipated expiration: 2032-01-14

Abstract

A gas generator cylinder cover and a sand mold thereof belong to the field of casting. The cylinder cover sand mold die comprises a pair of cylinder cover sand mold dies, a main body communicated with the pair of inner pouring gates to access to the sand mold dies is arranged on the cross pouring gate, a plurality of exhaust risers and exhaust needles are arranged on the upper surface of the cylinder cover sand mold die, a plurality of rectangular chills are arranged on the periphery of the cylinder cover sand mold die, a plurality of cylindrical chills are arranged in an upper hole of the cylinder cover, a plurality of shape-following chills are arranged on the special-shaped curved surface part of the periphery of the cylinder cover, sand cores are arranged in inner cavities of the sand mold dies, and casting sand molds are formed by utilizing the sand mold dies. The utility model can meet the performance requirements of reciprocating alternating high-heat circulation and high-pressure circulation of the cylinder cover of the gas generator, eliminate casting defects, realize the consistency of the performance of parts at different wall thicknesses and realize the compactness of the thick wall of a product.

Description

Gas generator cylinder cover and sand mold thereof

Technical Field

The utility model relates to a cylinder cover and a sand mold thereof, in particular to a gas generator cylinder cover and a sand mold thereof, and belongs to the field of casting.

Background

The traditional energy in the world gradually becomes exhausted, the environmental protection pressure becomes more and more severe, the development of new green and environmental-friendly energy is an important task for scientific and technological development, and the gas generator is one of the devices for developing new energy.

The cylinder cover is the most important part on the gas generator, the working condition is harsh, the reciprocating alternating high-temperature cycle and high-pressure cycle need to be borne, the common casting is difficult to bear the working condition, the casting is required to be made of alloy high-grade grey cast iron HT350, the internal structure is compact without any defect, the metallographic structure is all short A-type graphite, the casting comprises a top concave part, an air inlet, an air outlet and a plurality of holes, the minimum wall thickness of the casting is 6mm, the maximum wall thickness is 60mm, and the wall thickness difference is large, as the structure of the part is complex and the technical requirement is high, a plurality of domestic manufacturers can not produce qualified products by using a common casting method, the domestic manufacturers can not produce the parts, the vertical solid diagram of the cylinder cover casting is shown in figure 1, the inverted solid diagram of the cylinder cover casting is shown in figure 2, and the section along the A-A direction in figure 1 is shown in figure 3, fig. 4 is a schematic sectional view taken along the direction B-B in fig. 1, and fig. 5 is a schematic sectional view taken along the direction C-C in fig. 1. The cylinder cover of the gas generator is of an irregular structure, the upper surface, the lower surface, the left surface, the right surface and the two end surfaces of the cylinder cover of the gas generator are respectively provided with a plurality of holes which are communicated with the inside and have different sizes, the two end parts are respectively an air inlet end 13 and an air outlet end 14, the air inlet end 13 and the air outlet end 14 are respectively provided with an air inlet 21 and an air outlet 22, the upper part of the cylinder cover of the gas generator comprises a top sunken part 10, the sunken part 10 comprises a rabbit ear sunken part 11, a hollow part is arranged below the sunken part 10, four corners of the periphery of the hollow part are provided with pillars 12 which are lower than the sunken part 10, the periphery of the hollow part is provided with irregular holes, the sunken part 10 is communicated with the hollow part, the end surfaces of the air inlet end 13 and the air outlet end 14 of the cylinder cover of the gas generator are parallel, the bottom surface 20 of the cylinder cover is provided with a plurality of bottom holes 27, the side surfaces are also provided with a plurality of side surfaces, the side surfaces 15 and the middle side surfaces 16, the upper surface 23 and the bottom surface 20 are provided with a plurality of bottom holes 27.

Therefore, only import foreign products are relied upon, but import cylinder heads are not only expensive, but also subject to foreign restrictions.

In order to avoid being restricted by people, green new energy is developed, the localization of the cylinder cover of the gas generator is realized, the national development needs are met, and the development of the cylinder cover is a urgent matter for breaking through the domestic gas generator.

Disclosure of Invention

Aiming at the characteristics of complex cylinder cover structure and high manufacturing technical requirement, in order to realize the localization of products, the company develops research trial production of the gas generator cylinder cover from 2018, and finally succeeds in obtaining the gas generator cylinder cover and the sand mold thereof.

The technical scheme of the utility model is as follows: the utility model provides a gas generator cylinder cover, gas generator cylinder cover is irregular structure, set up respectively in the not equidimension hole that has a plurality of and inside intercommunication on the upper and lower face of gas generator cylinder cover, left and right sides and two terminal surfaces, both ends are the inlet end respectively and give vent to anger the end, be provided with air inlet and gas outlet respectively on the inlet end and the end of giving vent to anger, gas generator cylinder cover includes the top depressed part, the depressed part includes rabbit ear depressed part, the depressed part below is provided with well kenozooecium, be provided with the pillar that is less than the depressed part on the four corners of well kenozooecium periphery, well kenozooecium periphery is provided with irregular hole, depressed part and well kenozooecium intercommunication, the inlet end of gas generator cylinder cover and the end section of giving vent to anger are parallel.

A sand mold of a gas generator cylinder cover comprises a cross gate mold, an ingate mold, a sprue mold, an exhaust riser mold and an exhaust needle mold, wherein the cylinder cover sand mold comprises a pair of molds, the cylinder cover sand mold comprises an upper mold and a lower mold, a plurality of exhaust riser molds and exhaust needle molds are arranged on the upper mold, the cross gate mold and the sprue mold are arranged on one side of an air outlet end of a cylinder cover, the sprue mold is vertically arranged above the middle position of the cross gate mold between the pair of cylinder cover sand molds, the ingate molds of the two cylinder cover sand molds are symmetrically arranged on two sides of the sprue mold, the ingate mold is connected with a main body of the sand cover mold, the ingate mold and the cross gate mold are on the same horizontal plane and are vertical to each other, a plurality of rectangular chills are arranged on the periphery of the cylinder cover sand mold, and a plurality of cylindrical chills are arranged in an upper hole of the cylinder cover, a plurality of shape-following chills are arranged at the special-shaped curved surface part of the periphery of the cylinder cover, a sand core is arranged in an inner cavity of the sand mould, and a sand cavity is formed by utilizing the sand mould;

furthermore, rectangular chills with different sizes are respectively arranged at the top of the upper die, the bottom of the lower die, the side face of the sand die and the air outlet end above the ingate, conformal chills matched with the air outlet end of the sand die are arranged at the upper part of the air outlet end of the sand die and in the middle of the side face of the sand die, cylindrical chills are adopted in the hollow part in the cylinder cover and the sunken part of the cylinder cover, and the rectangular chills, the conformal chills and the cylindrical chills are all graphite chills;

furthermore, a plurality of exhaust riser models are arranged above the concave part of the upper mold, the exhaust riser models are higher than the upper surface of the corresponding sand box, exhaust needle models are respectively arranged above the upper mold corresponding to the middle positions of a plurality of mold pillars of the cylinder cover and the concave part, and the interior of each exhaust needle is of a taper structure;

further, the sprue model is arranged on the middle parting surface of an upper die and a lower die of the pair of sand molds, and a foamed ceramic molten iron filter model is arranged at the bottom of the sprue model;

further, the sand core is a coated sand core formed by mixing chromite sand and quartz sand;

further, the cross section ratio of the gating system formed by the ingate model, the horizontal runner model and the sprue model is as follows: f_{Inner part}：F_{Horizontal bar}：F_{Straight bar}=1：2.2：1.28；

Further, the thickness of the graphite chilling block is 0.5-1.2 times of the wall thickness of the corresponding casting part.

The utility model has the following positive effects: the upper die is provided with the plurality of exhaust riser models and the exhaust needle models, so that feeding and slag collection during molten metal pouring in a sand mold formed by the sand mold die are facilitated, excess gas in the sand mold die is discharged along the risers while the cavity is filled with the alloy liquid in the pouring process, the situation that the alloy liquid cannot be completely filled due to gas retention in the cavity can be prevented, and particularly, the exhaust risers are arranged at the narrow positions of the edges of the concave parts of the sand mold die, so that liquid feeding can be provided to a certain extent, and shrinkage cavities and shrinkage porosity of castings are prevented; the exhaust needles are arranged at the middle positions of the plurality of die table columns and the die concave parts of the cylinder cover, so that gas can be exhausted along the exhaust needles, and a casting is prevented from generating air holes; rectangular chills are arranged at the bottom surface, the top, the side surface and the sand mold plane part outside the end surface of the sand mold die, so that the slow solidification hot spot caused by large thickness and slow heat dissipation of the parts of the casting can be eliminated; by arranging the conformal chills at the curved surface part of the exhaust end of the upper die and the curved surface parts at the two sides of the upper die of the casting, the hot spot of the curved surface of the exhaust end can be eliminated; the cylinder head casting quality is improved by arranging a plurality of cylindrical graphite chills in the upper hole of the cylinder head, adopting a precoated sand core mixed by chromite sand and quartz sand as a core in the cavity, replacing the traditional precoated sand core by the precoated sand core mixed by chromite sand and quartz sand, replacing the traditional cylindrical precoated sand core by the cylindrical graphite chills, particularly adopting the graphite chills, and utilizing the characteristics of high refractoriness, strong heat storage capacity and high thermal conductivity of the graphite chills and the chromite sand to accelerate the overall cooling speed of the casting, refine the structure and avoid the shrinkage defect at a hot spot And the compactness of the thick wall of the product is realized.

Drawings

FIG. 1 is an upright perspective view of a cylinder head casting.

FIG. 2 is an inverted perspective view of the cylinder head casting.

Fig. 3 is a schematic sectional view along the direction a-a in fig. 1.

Fig. 4 is a schematic cross-sectional view taken along the direction B-B in fig. 1.

Fig. 5 is a schematic cross-sectional view along the direction C-C in fig. 1.

FIG. 6 is a perspective view of a vertical sand mold for the cylinder head.

Fig. 7 is a schematic structural diagram of a chill, a sprue mold, an exhaust riser mold and an exhaust pin mold arranged on the cylinder head upper mold.

FIG. 8 is a schematic structural view of a cylinder head lower mold provided with a chill.

Fig. 9 is a schematic diagram of a conformal chill structure on the end face of a sand mold.

Fig. 10 is a schematic structural diagram of a conformal chill II on the side surface of the sand mold.

FIG. 11 is a schematic view of a cylindrical chiller for a recess inner hole.

Fig. 12 is a schematic view of a structure of the sand core.

Fig. 13 is a schematic structural diagram of the second sand core.

Fig. 14 is a schematic view of the inverted configuration of sand core one.

Fig. 15 is a schematic back structure view of the second sand core.

Description of reference numerals: 10-concave part, 11-rabbit ear concave part, 12-pillar, 13-air outlet end, 14-air outlet end, 15-lower side surface, 16-middle side surface, 17-center hole, 18-concave part inner hole I, 19-concave part inner hole II, 20-bottom surface, 21-air inlet, 22-air outlet, 23-upper side surface, 24-middle thick platform, 25-side wall I, 26-side wall II, 27-bottom hole, 28-middle wall I, 29-middle wall II, 30-mold concave part, 31-mold concave ear part, 32-mold pillar, 33-mold air inlet end, 34-mold air outlet end, 35-mold lower side surface, 36-mold middle side surface, 37-mold upper side surface, 40a cross runner I, 40b cross runner II, etc, 41 a-ingate I, 41 b-ingate II, 42-sprue model, 43-molten iron filter model, 44-exhaust riser model, 45-exhaust needle model, 46 a-rectangular chiller I, 46 b-rectangular chiller II, 46 c-rectangular chiller III, 47 a-conformal chiller I, 47 b-conformal chiller II, 48-cylindrical chiller, 49-sand core I and 50-sand core II.

Detailed Description

The following detailed description of the embodiments of the present invention refers to the accompanying drawings. The cylinder head sand mold is arranged according to the shape of a cylinder head, and a mold concave part 30, a mold rabbit ear part 31, a mold pillar 32, a mold air inlet end 33, a mold air outlet end 34, a mold lower side surface 35, a mold middle side surface 36 and a mold upper side surface 37 in the sand mold correspond to the concave part 10, the rabbit ear concave part 11, the pillar 12, the air inlet end 13, the air outlet end 14, the lower side surface 15 and the middle side surface 16 of the cylinder head respectively.

The technical scheme of the utility model is that the utility model is a sand mould of a gas generator cylinder cover, FIG. 6 is a vertical sand mould of the cylinder cover, FIG. 7 is a structural schematic diagram of a cylinder cover upper mould provided with a chilling block, a sprue model, an exhaust riser model and an exhaust needle model, the cylinder cover sand mould comprises a cross runner model, an ingate model, a sprue model 42, an exhaust riser model 44 and an exhaust needle model 45, the cylinder cover sand mould comprises a pair of cylinder cover sand moulds, the cylinder cover sand mould comprises an upper mould and a lower mould, the upper mould is provided with a plurality of exhaust riser models 44 and exhaust needle models 45, the cross runner model and the ingate model are arranged at one side of a gas inlet end 13 of the cylinder cover, the sprue model is vertically arranged at the middle position of the cross runner model between the pair of cylinder cover sand moulds, the sprue model 42 is arranged above the upper mould, and two sides of the sprue model 42 are symmetrically provided with a first ingate model 41a and a second ingate model 41a of two cylinder cover moulds b, connecting an ingate model with a cylinder cover sand mold main body, enabling the ingate model and a cross gate model to be on the same horizontal plane and to be perpendicular to each other, arranging a plurality of rectangular chills on the periphery of the cylinder cover sand mold, arranging a plurality of cylindrical chills 48 in an upper hole of the cylinder cover, arranging a plurality of conformal chills on a special-shaped curved surface part on the periphery of the cylinder cover, arranging a sand core in an inner cavity of the sand mold, and showing a structural schematic diagram of the sand core in fig. 12, a structural schematic diagram of a sand core in fig. 13, a structural schematic diagram of a sand core in fig. 14 and a structural schematic diagram of the back of the sand core in fig. 15. The sand core casting device specifically comprises a first sand core 49 and a second sand core 50, wherein the sand cores form a sand cavity of a casting.

In this embodiment, the runner includes a first runner 40a and a second runner 40b, the first runner 40a and the second runner 40b are in a straight line and are respectively communicated with a sand mold cavity formed by a pair of sand mold dies through a first ingate 41a and a second ingate 41b, the first ingate 41a and the second ingate 41b are in the same plane with the first runner 40a and the second runner 40b, and a sprue model 42 is arranged in a vertical direction in the middle of the first ingate 40a and the second runner 40 b.

Fig. 9 is a schematic structural diagram of a conformal chiller of an end face of a sand mold, fig. 10 is a schematic structural diagram of a conformal chiller on a side face of the sand mold, and fig. 11 is a schematic structural diagram of a cylindrical chiller of an inner hole of a concave part. Go up the air inlet end 13 of mould top, bottom die's bottom, sand mould side and ingate top and be provided with the rectangle chill of variation in size respectively, the mould is given vent to anger and is provided with the shape-following chill that matches with it in the middle of end 34 upper portion and the sand mould side, and the intercommunicating pore of well kenozooecium adopts cylinder type chill 48 in cylinder head depressed part 10 and the cylinder head, cylinder type chill 48 includes the cylinder type chill of different diameters co-altitude, and rectangle chill, shape-following chill and cylinder type chill 48 are all graphite chills.

In the embodiment, the chilling block is placed in an oven to be baked for 2 hours at 250 ℃ before use, so that the water is fully dried, and the chilling block is used after being cooled to room temperature, and the defects of loose structure and shrinkage cavity and shrinkage porosity of a casting can be eliminated by the chilling block material adopted inside and outside the cylinder cover.

All casting out in the hole more than 10mm of diameter, wherein the hole of diameter 10 ~ 25mm adopts the chill of graphite preparation to replace the core, and the diameter is greater than 25 mm's hole and inner chamber psammitolite and adopts the tectorial membrane sand preparation psammitolite that chromite sand and quartz sand mix, and the mixing ratio is listed as, chromite sand: and (3) quartz sand = (0.3-0.7): 1, and vent holes are formed in the sand core during core making.

A plurality of exhaust riser models 44 are arranged above the upper die sunken part 30, the exhaust riser models 44 are higher than the upper surface of the corresponding sand box, exhaust needle models 45 are respectively arranged above the upper die corresponding to the middle positions of the plurality of die table columns 32 of the cylinder cover and the die sunken part 30, and the interior of each exhaust needle is of a taper structure.

In the embodiment, each cylinder head top is not provided with a large feeding head, 4 sand molds of each set of the exhaust head molds 44 are provided, 8 sand molds are provided, 4-6 exhaust head molds 44 are arranged on the top of the upper mold, the size of each exhaust head mold is 45mm multiplied by 8mm, the size of each upper opening is 50mm multiplied by 30mm, the height top surface exceeds the upper surface of the sand box, 137 exhaust needle molds 45 are further arranged on the top surface of each cylinder head, and the size of each exhaust needle mold is 14 sand molds, the top part is phi 8mm, and the bottom part is phi 13 mm. The height top surface exceeds the upper surface of the sand box.

The bottom of the sprue model 42 is provided with a ceramic foam molten iron filter model 43, and the size of the filter is 70 × 70 × 20mm in the embodiment.

The sand core is a coated sand core formed by mixing chromite sand and quartz sand, and fig. 5 is a schematic cross-sectional view along the C-C direction in fig. 1. In the figure, the first intermediate wall 28 and the second intermediate wall 29 are easy to generate thermal joints, and if no chilling measure is taken, shrinkage cavities or shrinkage porosity defects are generated inside, so that the first sand core 49 in the figure 12 and the second sand core 50 in the figure 13 are utilized, the heat dissipation of the parts is accelerated, the heat dissipation conditions inside the cylinder cover are improved, and the shrinkage cavities or shrinkage porosity defects are eliminated.

The cross section ratio of the gating system formed by the ingate model, the horizontal gate model and the sprue model 42 is as follows: f_{Inner part}：F_{Horizontal bar}：F_{Straight bar}= 1: 2.2: 1.28; the cross-sectional dimensions of the runner pattern in this embodiment are 30/36X 36mm, the cross-sectional dimensions of the ingate pattern are 12X 45mm, and the diameter of the bottom of the sprue pattern 42 is 42 mm.

The thickness of the graphite chilling block is 0.5-1.2 times of the wall thickness of the corresponding casting part.

Manufacturing a cylinder cover sand mold according to a process design, wherein the cylinder cover sand mold comprises an upper box template, a lower box template, an exhaust riser model 44, an exhaust needle model 45, a pouring system model and a precoated sand hot core box; secondly, machining a conformal chill according to the shape of a sand mold die, and manufacturing a required core by using a coated sand core shooter, wherein raw sand of the core is a mixture of quartz sand and chromite sand which account for half of the quartz sand and chromite sand respectively; thirdly, respectively installing the upper and lower moulds which are manufactured in advance on a molding machine, and placing a sand box on the template; fourthly, placing chill, a pouring gate and an exhaust hole pattern on the corresponding surface of the sand mould according to the design requirement; and fifthly, filling sand into the sand box according to normal production and molding, and simultaneously loading and unloading the sand box. According to the actual situation, the chill can be placed while filling sand until the molding is finished; sixthly, stripping and shaping, namely putting the manufactured chromite sand cores into the manufactured sand mould in sequence, and closing the mould to wait for pouring; seventhly, molten iron smelting can be synchronously carried out in the molding process, and the smelted molten iron is poured into a sand mold; and eighthly, preserving heat for a proper time after pouring, opening the box, shakeout, cleaning, polishing, annealing, performing shot blasting treatment again, inspecting and warehousing qualified products, and thus obtaining qualified cylinder cover castings.

In the embodiment, the molding machine sand box specification size is length × width × height =720mm × 520mm × 380/380mm, the gas generator cylinder head outline size is length × width × height =350mm × 220mm × 210mm, the clay green sand is molded, 2 pieces are molded in each box, the production line is adopted, and the box molding is adopted.

In this embodiment, the cross-sectional dimension of the ingate is width × height × length =45 × 12 × 20mm, the cross-sectional dimension of the runner is 30/36 × 36mm, the diameter of the bottom of the sprue model 42 is Φ 42mm, and the cross-sectional ratio of the gating system is: f_{Inner part}：F_{Horizontal bar}：F_{Straight bar}=1：2.2：1.28。

The specific operation method comprises the following steps:

fig. 3 is a schematic sectional view taken along a-a in fig. 1, and fig. 4 is a schematic sectional view taken along B-B in fig. 1. In the present example, graphite chillers were used, and the following specifications were shared,

firstly, a first rectangular chilling block 46a with the size of 100 multiplied by 70 multiplied by 20mm, a second rectangular chilling block 46b with the size of 80 multiplied by 50 multiplied by 40mm and a third rectangular chilling block 46c with the size of 100 multiplied by 40 multiplied by 20mm, wherein the first rectangular chilling block 46a is arranged on the bottom surface of a sand mold corresponding to the bottom surface 20 of the cylinder cover; the rectangular second chiller 46b is used for cooling the hot spot part of the air inlet end 13 at the lower part of the casting; the reason that the rectangular chiller III 46c is used for the bottom surface 20 of the casting close to the end part and the lower side surface 35 of the mold is that the thickness of the first side wall 25 and the second side wall 26 is large, so that compared with other parts, the heat is large, the heat dissipation is slow, and a heat node is easy to generate, and the rectangular chiller III 46c arranged on the side surface can eliminate the heat node generated by the first side wall 25 and the second side wall 26;

secondly, the first conformal chiller 47a and the second conformal chiller 47b are arranged at the upper part between the air outlet ports of the two sand molds at the air outlet end 34 of the mold, and are used for eliminating the curved surface heat node at the end part of the casting; the shape-following chiller II 47b is arranged at the middle side surface 36 positions of two sides of the mould, namely two sides of the upper part of the casting and is used for chilling the hot spot part of the curved surface, and the shape-following chiller I47 a and the shape-following chiller II 47b are special-shaped chills processed by a numerical control milling machine and are used for chilling the curved surface part on the casting;

and thirdly, the cylindrical chiller 48 comprises a size of 12 multiplied by 100mm and a size of phi 10 multiplied by 40mm, is used for forming small holes of castings, and is mainly used for forming a first sunken part inner hole 18 and a second sunken part inner hole 19 of the sunken part 10 of the cylinder cover.

The specific implementation method of the utility model is as follows:

1. manufacturing a cylinder cover sand mold according to drawing requirements provided by a gas generator equipment user, wherein the cylinder cover sand mold comprises an upper mold lower mold template, an exhaust riser mold 44, an exhaust needle mold 45, a casting riser mold, a film-coated hot sand core, and casting shrinkage, machining allowance and drawing inclination according to casting process requirements;

2. designing a conformal chill according to the shape of a sand mould die, processing the chill, preparing a sand box, purchasing precoated sand according to the proportion of half of each of quartz sand and chromite sand, and manufacturing a required sand core by using a precoated sand core shooter;

3. respectively installing a lower die of an upper die and a template thereof which are manufactured in advance on a molding machine, and placing a prepared special sand box on the template;

4. placing the processed various chills, the pouring gate model and the exhaust hole model on the corresponding surfaces of the sand mold according to the design requirements, wherein the chills are required to be tightly attached to the sand mold at the placed positions;

5. and filling sand into the sand box according to normal production for molding, and loading and unloading the sand box simultaneously. According to the actual situation, the chill can be placed while filling sand until the molding is finished;

6. stripping and shaping, namely putting the manufactured chromite sand cores into the manufactured sand mould in sequence, and closing the mould to wait for pouring;

7. in the molding process, metal furnace charge, molten metal smelting, chemical examination and chemical composition adjustment can be synchronously prepared, and the smelted molten iron is poured into a sand mold;

8. and preserving heat for a proper time after pouring, opening the box, shakeout, cleaning, polishing, annealing, performing shot blasting treatment again, inspecting, and warehousing to obtain a qualified cylinder cover casting.

The cylinder cover produced by the chill and the sand core structure of the utility model has no casting defects inside and outside, has excellent mechanical properties and metallographic structure, completely meets the requirements of users, and can replace imported products.

The above-mentioned embodiments are only preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and it can be applied to the production of cylinder heads of gas generators with different specifications, and also can be applied to the production of other similar iron castings by using the structure, and the sizes of the exhaust riser model 44, the exhaust pin model 45 and the sprue model 42 should not be limited above, and can be changed as required. The material and size of the chiller should not be limited as above, and can be changed according to the design requirement.

The utility model is beneficial to feeding and slag collection in molten metal forming by arranging a plurality of exhaust riser models and exhaust needle models 45 on the upper die, is beneficial to discharging redundant gas along risers when the die cavity is filled with the alloy liquid in the casting process, can prevent the alloy liquid from being incompletely filled because the gas is retained in the die cavity, in particular, the exhaust riser models 44 are arranged at the middle thick platform 24 in the middle of the die concave part 30 and the upper end of the upper side surface 37 of the die at the edge, can provide liquid feeding by the exhaust riser at the top when the liquid is contracted after the melted alloy liquid is cast in a sand mold, can keep the temperature to a certain degree, prevent the alloy liquid from being solidified prematurely, is beneficial to discharging the gas along the exhaust needles by arranging the exhaust needle models 45 at the middle positions of a plurality of die column 32 ends of the cylinder cover and the die concave part 30 corresponding to the center hole 17 of the cylinder cover, the alloy liquid can be smoothly reached; rectangular chills are arranged at sand mold plane parts on the bottom surface, the top, the side surfaces and the outer side of the end surface of the mold, so that a chiller action zone is ensured, the chilling effect can be ensured to reach a central layer of a casting, the casting cannot crack, and chills molten metal by fully distributing the chills on the six side surfaces of the casting, so that the solidified metal has a fine and dense internal structure, does not leak, has fine crystal grains, high strength and reliable service performance; by arranging the conformal chills at the curved surface part of the exhaust end of the upper die and the curved surface parts at the two sides of the upper die of the casting, the hot spot at the curved surface part of the exhaust end can be eliminated; the cylinder type graphite chill is adopted, and the sand core arranged in the cavity adopts a coated sand core mixed by chromite sand and quartz sand, so that all parts of the inner cavity of the casting can be solidified basically simultaneously when molten metal is crystallized and solidified, and products with excellent mechanical properties and metallographic structures are finally obtained and completely replace imported products; the utility model can meet the performance requirements of reciprocating alternating high-temperature circulation and high-pressure circulation of the cylinder cover of the gas generator, eliminate casting defects, realize the consistency of the performance of parts at different wall thicknesses and realize the compactness of the thick wall of a product.

Claims

1. The utility model provides a gas generator cylinder head and sand mould thereof, includes cross gate model, ingate model, sprue model, exhaust rising head model and exhaust needle model, its characterized in that: the cylinder cover sand mold comprises a pair of cylinder cover sand molds, each cylinder cover sand mold comprises an upper mold and a lower mold, a plurality of exhaust riser molds and exhaust needle molds are arranged on the upper surface of the upper mold, a horizontal gate mold and an ingate mold are arranged on one side of an air outlet end of a cylinder cover, a sprue mold is vertically arranged above the middle position of the horizontal gate mold between the pair of cylinder cover sand molds, the ingate molds of the two cylinder cover sand molds are symmetrically arranged on two sides of the sprue mold, the ingate molds are connected with a main body of the cylinder cover sand mold, the ingate molds and the horizontal gate molds are on the same horizontal plane and are perpendicular to each other, a plurality of rectangular chills are arranged on the periphery of the cylinder cover sand mold, a plurality of cylindrical chills are arranged in an upper hole of the cylinder cover, a plurality of conformal chills are arranged on the irregular curved surface part of the periphery of the cylinder cover, sand molds are internally provided with sand cores, and the sand molds are used for forming cavities.

2. The gas generator cylinder cover and the sand mold thereof according to claim 1, wherein: the mould is characterized in that air outlet ends of the top of the upper mould, the bottom of the lower mould, the side face of the sand mould and the upper side of the ingate are respectively provided with rectangular chills with different sizes, shape-following chills matched with the air outlet ends of the sand mould are arranged in the middle of the upper part of the air outlet end of the sand mould and the side face of the sand mould, cylindrical chills are adopted as communication holes of the hollow part in the cylinder cover and the cylinder cover, and the rectangular chills, the shape-following chills and the cylindrical chills are all graphite chills.

3. The gas generator cylinder cover and the sand mold thereof according to claim 1, wherein: and a plurality of exhaust riser models are arranged above the sunken part of the upper mold, the exhaust riser models are higher than the upper surface of the corresponding sand box, exhaust needle models are respectively arranged above the upper mold corresponding to the middle positions of the plurality of mold pillars and the sunken part of the cylinder cover, and the inside of each exhaust needle is of a taper structure.

4. The gas generator cylinder cover and the sand mold thereof according to claim 1, wherein: the sprue model is arranged on the parting surface between the upper die and the lower die of the pair of sand molds, and the bottom of the sprue model is provided with a foamed ceramic molten iron filter model.

5. The gas generator cylinder cover and the sand mold thereof according to claim 1, wherein: the sand core is a coated sand core formed by mixing chromite sand and quartz sand.

6. The gas generator cylinder cover and the sand mold thereof according to claim 1, wherein: the cross section ratio of the gating system formed by the ingate model, the horizontal gate model and the sprue model is as follows: f_{Inner part}：F_{Horizontal bar}：F_{Straight bar}=1：2.2：1.28。

7. The gas generator cylinder cover sand mold die according to claim 2, wherein: the thickness of the graphite chilling block is 0.5-1.2 times of the wall thickness of the corresponding casting part.