CN106623795A - Running and feeding system on DISA line of small-size cylinder gray iron castings and design method of running and feeding system - Google Patents

Abstract

The invention relates to a running and feeding system on a DISA line for producing small-size cylinder gray iron castings and a design method of the running and feeding system. The running and feeding system is characterized in that the running and feeding system comprises feeder heads and a pouring system, wherein the pouring system comprises inner runners, straight runners and a transverse runner; eight castings are distributed in each template; two sides of the transverse runner are respectively provided with one straight runner by using a running cup as a symcenter in a left-right symmetry way; each straight runner is divided into an upper layer and a lower layer and is provided with four castings, and the four castings are symmetrically distributed by using each straight runner as the axis; each casting is communicated with the corresponding straight runner through the corresponding inner runner; a buffer zone is arranged at the lower end of each straight runner; the section shapes of the inner runners are rectangular; the section shapes of the straight runners and the transverse runner are isosceles trapezoidal; the section areas of the eight castings are equal; the section area of the transverse runner is 6.25 times that of the section area of a single inner runner; the section area of the straight runner located in the upper layer is 4.8 times that of the section area of a single inner runner, and the section area of the straight runner located in the lower layer is 1.9 times that of the section area of a single inner runner.

Description

The pouring and riser system and its design method on the DISA line of small cylinder gray iron castings

technical field

The invention belongs to the technical field of cast iron technology, and in particular relates to a casting riser system and a design method thereof on a DISA line of a small cylinder gray iron casting.

Background technique

Casting production is a production method of liquid metal forming. The process of liquid metal entering the mold, cooling and solidifying to form metal products is casting production, referred to as casting, and the produced metal products are called castings. The vast majority of castings are used as blanks and need to be machined before they can become various machine parts; a few castings that meet the requirements of dimensional accuracy and surface roughness can be used directly as finished products or parts.

When adopting the casting process in the prior art to produce, usually in the top of the casting, near the riser, the final solidification position, the thick wall of the casting and the vicinity of the ingate, etc., the solidification is late or the position of solidification is slow (commonly referred to as It is a hot section), resulting in the defects of shrinkage cavity and shrinkage porosity. When the casting has shrinkage cavity defects, the metal continuity becomes poor, the effective bearing area becomes smaller, and it is easy to form stress concentration at these defect parts, thereby affecting the mechanical and mechanical properties of the casting. In addition, the original process technology is adopted, and the process yield rate of castings is low.

The modern foundry industry generally adopts automatic production lines to produce castings, among which DISA production line is a common equipment for mass production of small iron castings. DISA production line adopts compressed air extrusion molding, which has good sand compactness and high production efficiency, and is suitable for producing ductile iron and gray iron castings with medium and complex structures and high precision requirements.

However, DISA line equipment also has some shortcomings. DISA line equipment limits the casting process to vertical parting, and there is only one parting surface, and the gate position is fixed within a small range. The characteristics of DISA line equipment determine the particularity of its casting process. The characteristic of the DISA line casting process is that the castings are arranged in layers. In order to ensure the uniformity and stability of the casting quality, it is required that the castings of each layer be filled at the same time when filling the mold; in order to improve production efficiency, the gating system and the riser system are required to be compactly arranged, so Foundries often design risers and gating systems together. Figure 2 is the pattern layout of the original gating riser system. There are 9 castings arranged in a pattern. It can be seen that the original process has the following shortcomings: (1) 9 castings are arranged in the pattern, which is divided into three layers. Arrangement, resulting in too lengthy sprue design in the original gating system. (2) At the same time, the design size of the riser and runner in the gating system is too large, resulting in a very low process yield. Moreover, because the design of the sprue adopts a constant pressure and other flow process scheme, the lowermost pressure head of the sprue is too large. When pouring the casting, the flow rate of the molten metal is too high, and the osmotic pressure of the lower inner runner is large, causing the lower casting to produce Pores, burr defects. (3) In the original process, in order to improve production efficiency, the foundry often integrates the riser and the gating system to design and calculate, and cannot take into account the technical requirements of both at the same time. The design and calculation mainly rely on experience. Although after repeated experiments and adjustments, still Shrinkage cavity defects near sprue castings cannot be eliminated. (4) The original casting process adopts the principle of constant pressure and other flow to design the gating system. There is no separate riser for each casting during pouring, and only the sprue is used to feed shrinkage, and simultaneous filling cannot be guaranteed, which affects the quality of the casting.

At present, foundry enterprises adopting the DISA line generally design the gating system according to the design method given by the DISA company, and design the riser by adopting an empirical method similar to the design of the cast iron riser, which lacks strict scientificity, so the produced castings often have shrinkage cavities. Pine and other defects, and the process yield is very low (generally around 50%). The gray iron casting of a small cylinder body studied by the present invention is a kind of gray iron casting. Such a situation occurs in actual pouring, the process yield is low (63.5%), and shrinkage defects are prone to occur.

Contents of the invention

In view of the above-mentioned problems, the technical problem to be solved by the present invention is to provide a disa-line gating and riser system and its design method for small cylinder gray iron castings. The gating and riser system can greatly increase the yield of castings, reduce shrinkage porosity and shrinkage cavity defects, and finally obtain small cylinder gray iron castings with good quality.

The technical solution adopted by the present invention to solve the technical problem is:

A disa-line gating riser system for small gray iron castings, characterized in that the gating riser system includes a riser and a gating system, and the gating system includes an inrunner, a sprue and a runner, Eight castings are arranged in each template, and a sprue is symmetrically arranged on the left and right sides of the runner with the sprue cup as the center, and four castings are arranged on the upper and lower layers of each sprue, and each The sprue is axisymmetrically distributed, and each casting communicates with the sprue through the corresponding sprue; a buffer area is provided at the lower end of each sprue; the cross-sectional shape of the sprue is rectangular; the sprue The cross-sectional shape of the runner and the runner are all isosceles trapezoidal, the cross-sectional area of the eight inner runners is equal, and the cross-sectional area of the runner is 6.25 times that of a single inner runner, and the cross-sectional area of the sprue located on the upper layer The area is 4.8 times the cross-sectional area of a single ingate, and the cross-sectional area of the sprue at the lower layer is 1.9 times that of a single ingate; the risers are separately arranged directly above each casting.

A design method for the above-mentioned gating riser system on the DISA line. When designing the riser, the graphitization expansion of gray cast iron is taken into consideration, and the size and shape of the riser are calculated by using the principle of equilibrium solidification; when designing the gating system , first add the riser mass calculated by the principle of equilibrium solidification and the corresponding casting mass, and then calculate the cross-sectional area of the ingate, sprue, and runner according to the equal pressure and flow process design method, and finally The optimal cross-sectional shape and size of each sprue are obtained through numerical simulation.

Compared with prior art, the beneficial effect of the present invention is:

1) Under the premise of ensuring the elimination of shrinkage and shrinkage defects of castings, the design size of the riser and gating system was reduced, so that the process yield of castings increased from 63.5% to 74.1%;

2) The original casting process combines the riser and gating system for design calculation, which cannot take into account the technical requirements of the two at the same time. The design calculation mainly relies on experience. Although it has been adjusted repeatedly through experiments, it still cannot eliminate the shrinkage and porosity defects in the center of the casting. Yield is also low. The design and calculation of the riser and gating system of the casting process of the present invention are clear and accurate, and each casting is provided with a riser separately, fully considering the graphitization expansion, and the riser is designed using the equilibrium solidification theory, which greatly reduces the volume of the riser , and use numerical simulation technology for evaluation and optimization, which greatly improves the scientificity and reliability of the design;

3) The original casting process uses constant pressure and other flow principles to design the gating system, and the castings cannot be filled at the same time during pouring, which affects the quality of the castings. However, the present invention adopts the equal pressure and equal flow process design method to design the gating system, which reduces the cross-sectional area of the sprue, effectively reduces the cross-sectional area of the previous sprue, and effectively improves the shrinkage cavity of the castings close to the sprue. The trend, and the designed gating system can ensure that each casting reaches equal pressure, equal flow rate, equal flow rate, and is filled at the same time. The process design is relatively simple, and the structure of each riser is the same for practical operation. It is suitable for DISA automatic scale production and prevents the quality difference of each casting.

4) The amount of sand eaten in the original process is too small, which will cause potential safety hazards. However, the design method of the present invention readjusts the distribution of the mold plates of the castings, changing the original process from 9 pieces of the first type to 8 pieces of the first type, reducing the sprue On the premise of improving the yield rate of the casting process, the size of the pouring riser system is significantly reduced, the space is saved, the production process is safer, and the pouring process is guaranteed to be carried out smoothly and the production efficiency is high. The small cylinder produced by the present invention is obtained. The pattern layout of the gating and riser system on the DISA line of the body gray iron casting.

Description of drawings

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

Fig. 1 is the layout of the pouring riser system template on the DISA line of the small cylinder gray iron casting of the present invention;

Figure 2 is the pattern layout of the original gating riser system;

Figure 3 is a schematic diagram of shrinkage porosity corresponding to the original gating riser system; Figure 3(a) is a schematic diagram of shrinkage porosity corresponding to castings produced under the original gating riser system; Figure 3(b) is a corresponding production corresponding to the original gating riser system Shrinkage cavity diagram;

Fig. 4 is a schematic diagram of shrinkage porosity corresponding to castings produced under the gating riser system of the present invention; wherein Fig. 4 (a) is a corresponding shrinkage porosity schematic diagram of castings produced under the gating riser system of the present invention; Fig. 4 (b) is the present invention Schematic diagram of the shrinkage cavity corresponding to the casting produced under the gating riser system;

Fig. 5 is a schematic structural view of a small cylinder gray iron casting according to an embodiment of the present invention, Fig. 5 (a) is a front view, Fig. 5 (b) is a left view, Fig. 5 (c) is a top view, Fig. 5 (d) is an isometric drawing;

In the figure, 1 casting, 2 riser, 3 ingate, 4 sprue, 5 sprue cup, 6 runner, 7 buffer area.

detailed description

The present invention will be further described below in conjunction with the embodiments and accompanying drawings, but this should not be used as a limitation to the protection scope of the claims of the present application.

The pouring riser system (abbreviation pouring riser system, referring to Fig. 1) on the DISA line of the small cylinder gray iron casting (casting for short) of the present invention comprises a riser and a pouring system, and the pouring system includes an ingate 3, a straight Runner 4 and runner 6, eight castings are arranged in each pattern plate, and a sprue 4 is symmetrically arranged on the left and right sides of the runner cup 5 on the left and right sides of the runner cup 5, and each sprue is divided into There are four castings arranged on the upper and lower layers, and each sprue is symmetrically distributed, and a riser 2 is set directly above each casting. The casting is communicated with the sprue 4 through the corresponding ingate 3; a buffer area 7 is provided at the lower end of each sprue 4; the cross-sectional area of the ingate 3 is calculated using the equal pressure and flow process design method, The cross-sectional shape is rectangular; the cross-sectional shapes of the sprue and the runner are both isosceles trapezoidal, and the cross-sectional areas of the eight inner runners are all equal, and the cross-sectional area of the runner 6 is 6.25% of the cross-sectional area of the single inner runner 3 times, the sectional area of the sprue on the upper layer is 4.8 times that of a single ingate 3, and the sectional area of the sprue on the lower layer is 1.9 times that of a single ingate.

The graphitization expansion of gray cast iron is taken into consideration in the design of the riser 2, the size of the riser is calculated by using the equilibrium solidification theory, and a square riser without riser pocket is selected.

The cross section mentioned in the present invention refers to the cross section of the corresponding runner.

The design method of the pouring riser system on the DISA line of the small cylinder gray iron casting of the present invention is: when designing the riser, the graphitization expansion of the gray cast iron is taken into consideration, and the size and shape of the riser are calculated by using the principle of equilibrium solidification ; When designing the gating system, firstly add the riser mass calculated by the principle of balanced solidification and the corresponding casting mass, and then calculate the inner sprue, sprue, and horizontal pouring according to the equal pressure and flow process design method. The cross-sectional area of the runner, and finally the optimal cross-sectional shape and size of each runner are obtained through numerical simulation.

The specific steps are:

The first step: the selection of casting process equipment

According to the characteristics of small cylinder gray iron castings and the production conditions of DISA line, sand casting is selected, vertical parting, riser and gating system are set on the parting surface.

Step 2: Riser design

1) Calculation of basic parameters and basic quantities of castings

It is known that the material of the small cylinder gray iron casting is HT200, the volume of the casting is v _c , the surface area of the casting is sc , and the density of the casting is ρ; according to the mass calculation formula, the mass of the casting is calculated as m _c = _{ρ.v c ;} The definition of the geometric modulus calculates the geometric modulus of the casting as

₂ ) Calculate the quality perimeter quotient Qm, gray iron casting shrinkage time fraction Pc, shrinkage modulus factor f2 and shrinkage modulus Ms; quality perimeter quotient:

Gray cast iron shrinkage time fraction:

Shrink modulus factor:

Shrinkage modulus of casting: M _s =f ₂ ·M _c

3) Calculate the riser modulus, determine the shape and size of the riser

The riser modulus is M _r ＝ M _C · f ₁ · f ₂ · f ₃ ;

Among them, f1 is the balance factor _of the riser, the value _of f1 is 1.3, and _f3 is the pressure factor of the riser, and the value of _f3 is related to the perimeter quotient of the casting quality, which can be obtained according to the calculated _Qm look-up table;

According to the above-mentioned riser modulus, the shape of the riser is taken as a square riser without nest. Since the riser only acts as a feeder, it is determined according to experience that H/A=1.1, B/A=1.1 (wherein H is the height of the riser body, A is the width of the riser body, B is the length of the riser body), and then the riser size is obtained by looking up the table;

4) Calculate the modulus of the riser neck and determine the shape and size of the riser neck

The modulus of the riser neck is M _n ＝ M _C · f _P · f ₂ · f ₄ , select a cuboid riser neck,

Among them, f ₄ is the length factor of the riser neck, and the value of f ₄ is 0.8; f _P is the flow effect factor, and the value of f _P is 0.5;

Riser neck thickness: e=(2～2.5)M _n ,

Riser neck width: W≥5e,

Riser neck length: l<=3e,

Determine the size of the riser neck according to the principle of "short, thin and wide";

Step Three: Gating System Design

1) sprue cup

According to the sum of the quality of a single casting and riser and the requirements of the process yield rate, select the sprue cup and adopt automatic molding;

2) Sprue design

The cross-sectional area S ₁ of a single ingate is calculated by using the equal pressure and equal flow process design method:

Among them, G is the mass of molten metal flowing through the cross-sectional area of the ingate, which is the sum of the mass of molten metal occupied by a riser and a casting in the present invention; μ is the flow coefficient, and μ takes a value of 0.35; τ is the metal The time for the liquid to flow through the cross-sectional area is determined according to factors such as the solidification time of the casting; g is the acceleration of gravity; H _p is the actual pressure head;

The cross-sectional area of the runner S4 is 6.25 times the cross-sectional area of the single gate S1, the cross _- sectional area S2 _of the sprue located _on the upper layer is 4.8 times that of the single gate cross-sectional area S1, and the cross-sectional area of the sprue located on the lower layer S ₃ is 1.9 times the cross-sectional area S ₁ of a single ingate.

After numerical simulation and debugging, it is determined that the best cross-section shape of the inner runner is a rectangle, the cross-section shape of the runner is an isosceles trapezoid, and the cross-section shape of the sprue is an isosceles trapezoid. .

The small cylinder gray iron castings described in the present invention generally exist in household appliances and are suitable for automatic scale production by DISA. The specific shape is shown in Figure 5. It has a protruding part that can play a supporting role, and the overall shape is relatively complicated.

Example 1

The gating riser system on the DISA line of the small cylinder gray iron casting in this embodiment includes a riser and a gating system, and the gating system includes an inrunner 3, a sprue 4 and a runner 6, and in each template Eight castings are arranged, and the runner 6 is symmetrically provided with a sprue 4 on the left and right sides with the sprue cup 5 as the center, and four castings are arranged on the upper and lower layers of each sprue, and each sprue The channels are axisymmetrically distributed, and risers 2 are separately set above each casting, and the castings on both sides of the sprue on the same layer are placed on the front and back sides, and each casting is connected with the sprue 4 through the corresponding ingate 3; A buffer area 7 is provided at the lower end of each sprue 4; the cross-sectional area of the ingate 3 is calculated using the equal pressure and flow process design method, and the cross-sectional shape is rectangular; the cross-sectional shape of the sprue and runner All are isosceles trapezoidal, the cross-sectional area of the eight ingates is equal, the cross-sectional area of the runner 6 is 6.25 times the cross-sectional area of a single ingate 3, and the cross-sectional area of the sprue on the upper layer is 6.25 times that of a single ingate. 4.8 times the cross-sectional area of channel 3, and the cross-sectional area of the sprue located in the lower layer is 1.9 times that of a single ingate.

The riser of this embodiment is a square riser without a riser socket, and the riser neck is a cuboid riser neck.

The basic parameters of the casting in this embodiment are: the casting material is HT200, the casting volume V _C =204215.1562mm ³ , the casting surface area S _C =44197.2478mm ² , the casting density ρ=6.45*10 ^-6 kg/mm ³ ,

The specific design steps of the gating riser system are as follows:

The first step: the selection of casting process equipment

According to the characteristics of small cylinder gray iron castings and the production conditions of DISA line, sand casting is selected, vertical parting, riser and gating system are set on the parting surface.

Step Two: Riser Design

1) Setting of basic parameters of castings and calculation of basic quantities

Casting material: HT200, casting volume V _C ＝204215.1562mm ³ , casting surface area S _C ＝44197.2478mm ² , casting density ρ＝6.45*10 ^-6 kg/mm ³ ;

Calculate the mass of the casting according to the mass calculation formula: m _C = ρ V _C = 1.32kg; calculate the geometric modulus of the casting according to the definition of the geometric modulus:

2) Calculation of mass perimeter quotient, shrinkage time fraction of gray iron castings, shrinkage modulus factor and shrinkage modulus of castings

Quality Perimeter Quotient:

Shrinkage time fraction of gray iron castings:

Shrink modulus factor:

Shrinkage modulus of casting

M _S =M _C ·f ₂ =0.383cm

4) Calculate the modulus of the riser and determine the shape and size of the riser

Riser modulus: M _r =M _C ·f ₁ ·f ₂ ·f ₃ , then M _r =0.462*1.2*0.83*1.3=0.6cm, where f ₁ is the riser balance factor, take f ₁ =1.2 ; f ₃ is the riser pressure factor, according to Q _m =13.39kg/mm ³ look-up table: f ₃ =1.3. The shape of the riser is a square riser without a riser socket. According to experience, it is determined that H/A=1.1, B/A=1.1, (where H is the height of the riser body, A is the width of the riser body, and B is the length of the riser body) Its size is 28mm x 25mm x 30mm.

5) Calculate the modulus of the riser neck and determine the shape and size of the riser neck

Riser neck modulus: M _n ＝ M _C · f _p · f ₂ · f ₄ , then M _n ＝0.462*0.5*0.83*0.8＝0.153cm

where f ₄ =0.8, f _P =0.5

Riser neck thickness: e=(2～2.5)M _n ＝4mm

Riser neck width: w≥5e=20mm,

Riser neck length: l≤3e=5mm,

According to the principle of "short, thin and wide" riser neck, the size of the riser neck is 4mm×30mm×5mm.

Step Three: Gating System Design

1) sprue cup

The weight of each casting plus riser is 1.5kg, 8 pieces per type, the tentative process yield rate is 75%, automatic molding is adopted, and No. 1 sprue cup is selected.

2) Sprue design

Calculate the cross-sectional area S ₁ of a single ingate by using the equal pressure and equal flow process design method:

which is

Among them, G is the sum of the mass of each casting and riser;

μ is the flow coefficient, the value is 0.35;

ρ is the density of casting material, its value is 6.45*10 ^-3 g/mm ³ ;

τ is the time for the molten metal to flow through the cross-sectional area of the ingate, which is determined according to factors such as the solidification time of the casting, and the value is 1;

g is the acceleration due to gravity;

_HP is the actual pressure head, which is 120mm in this embodiment.

The runner cross-sectional area S ₄ is 6.25 times of the single gate cross-sectional area S ₁ , that is, S ₄ =6.25 S ₁ =300mm ² ,

The cross-sectional area of the sprue on the upper layer is 4.8 times the cross-sectional area of a single ingate 3, that is, S ₂ =4.8 S ₁ =230.4mm ² ,

The cross-sectional area of the sprue located in the lower layer is 1.9 times the cross-sectional area of a single ingate, that is, S ₃ =1.9 S ₁ =91.2mm ² ,

After numerical simulation, optimization and debugging, it is finally determined that the cross-sectional shape of the ingate is rectangular, and the cross-sectional area of the ingate is 48mm ² ; The cross-sectional area of the runner is 300mm ² , the cross-sectional area of the sprue on the upper layer is 232mm ² , and the cross-sectional area of the sprue on the lower layer is 91mm ² ; so far the design of the gating system is completed.

According to the above design, the gating and riser system is obtained, and the pattern plate layout is one pattern with eight pieces, as shown in Figure 1.

The gating and riser system designed in this embodiment is used to simulate with numerical simulation software, and the result is shown in Figure 4, and Figure 3 is the vertical simulation of shrinkage porosity and shrinkage defects of the gating and riser system of the original technology. It can be seen that the parts that are prone to shrinkage and porosity under the process corresponding to the original gating and riser system completely disappeared under the process of the gating and riser system in this embodiment, that is, the castings obtained in this embodiment have no shrinkage and porosity defects, and this Examples also have no shrinkage cavity. Through calculation, the process productivity of the casting in this embodiment is increased from 63.5% to 74.1%, the process yield is significantly improved, and finally a good quality casting is obtained.

The above examples show that the application can effectively improve the quality of castings, reduce shrinkage porosity and shrinkage cavity defects, obtain castings with good surface quality, and significantly improve the yield of castings, and the gating system has a simple structure and is convenient for popularization and application.

What is not mentioned in the present invention is applicable to the prior art.

Claims (4)

1. A kind of pouring riser system on the DISA line of small cylinder gray iron casting, it is characterized in that this pouring riser system comprises riser and gating system, and described gating system comprises inner sprue, sprue and horizontal pouring There are eight castings arranged in each template, and a sprue is symmetrically arranged on the left and right sides of the sprue cup as the center of the runner. Four castings are arranged on the upper and lower layers of each sprue. Each sprue is axisymmetrically distributed, and each casting communicates with the sprue through a corresponding sprue; a buffer area is provided at the lower end of each sprue; the cross-sectional shape of the sprue is rectangular; The cross-sectional shape of the runner and the runner is isosceles trapezoidal, and the cross-sectional area of the eight inner runners is equal, and the cross-sectional area of the runner is 6.25 times that of a single inner runner. The cross-sectional area of the sprue is 4.8 times that of a single inner runner, and the cross-sectional area of the sprue at the lower layer is 1.9 times that of a single inner runner; the risers are separately arranged directly above each casting. 2. The pouring riser system on the DISA line of the small cylinder gray iron casting according to claim 1, characterized in that the riser is a square riser without a riser socket. 3. A design method of the pouring riser system on the DISA line of the small cylinder gray iron casting described in claim 1 or 2 is: when the riser is designed, the graphitization expansion of the gray cast iron is taken into consideration, and a balanced The solidification principle calculates the size and shape of the riser; in the design of the gating system, firstly, the mass of the riser calculated by the principle of equilibrium solidification and the corresponding casting mass are added together, and then calculated according to the equal pressure and flow process design method The cross-sectional area of the inner sprue, sprue, and runner, and finally the optimal cross-sectional shape and size of each sprue are obtained through numerical simulation. 4. The design method according to claim 3, the concrete steps of the method are: The first step: the selection of casting process equipment According to the characteristics of the gray iron castings of the small cylinder body and the production conditions of the DISA line, sand casting is selected, the vertical parting, the riser and the gating system are set on the parting surface; Step 2: Riser design 1) Calculation of basic parameters and basic quantities of castings It is known that the material of the small cylinder gray iron casting is HT200, the volume of the casting is v _c , the surface area of the casting is sc , and the density of the casting is ρ; according to the mass calculation formula, the mass of the casting is calculated as m _c = _{ρ.v c ;} The definition of the geometric modulus calculates the geometric modulus of the casting as ₂ ) Calculate the quality perimeter quotient Qm, gray iron casting shrinkage time fraction Pc, shrinkage modulus factor f2 and shrinkage modulus Ms; Quality Perimeter Quotient: Gray cast iron shrinkage time fraction: Shrink modulus factor: Shrinkage modulus of casting: M _s =f ₂ ·M _c 3) Calculate the riser modulus, determine the shape and size of the riser The riser modulus is M _r ＝ M _C · f ₁ · f ₂ · f ₃ ; Among them, f1 is the balance factor _of the riser, the value _of f1 is 1.3, and _f3 is the pressure factor of the riser, and the value of _f3 is related to the perimeter quotient of the casting quality, which can be obtained according to the calculated _Qm look-up table; According to the above-mentioned riser modulus, the shape of the riser is taken as a square riser without nest, and then the size of the riser is obtained by looking up the table; 4) Calculate the modulus of the riser neck and determine the shape and size of the riser neck The modulus of the riser neck is M _n ＝ M _C · f _P · f ₂ · f ₄ , select a cuboid riser neck, Among them, f ₄ is the length factor of the riser neck, and the value of f ₄ is 0.8; f _P is the flow effect factor, and the value of f _P is 0.5; Riser neck thickness: e=(2～2.5)M _n , Riser neck width: W≥5e, Riser neck length: l<=3e, Determine the size of the riser neck according to the principle of "short, thin and wide"; Step Three: Gating System Design 1) sprue cup According to the sum of the quality of a single casting and riser and the requirements of the process yield rate, select the sprue cup and adopt automatic molding; 2) Sprue design The cross-sectional area S ₁ of a single ingate is calculated by using the equal pressure and equal flow process design method: Among them, G is the mass of molten metal flowing through the cross-sectional area of the ingate; μ is the flow coefficient; τ is the time for the molten metal to flow through the cross-sectional area, which is determined according to factors such as the solidification time of the casting; g is the acceleration of gravity; H _p is the actual pressure head; The cross-sectional area of the runner S4 is 6.25 times the cross-sectional area of the single gate S1, the cross _- sectional area S2 _of the sprue located _on the upper layer is 4.8 times that of the single gate cross-sectional area S1, and the cross-sectional area of the sprue located on the lower layer S ₃ is 1.9 times the cross-sectional area of a single ingate S ₁ ; After numerical simulation and debugging, it is determined that the optimal cross-section shape of the inner runner is a rectangle, the cross-section shape of the runner is an isosceles trapezoid, and the cross-section shape of the sprue is an isosceles trapezoid. So far, the design of the gating system has been completed.