Die-casting pouring gate for solving shrinkage of air hole in middle of multi-cylinder body

Abstract

The utility model relates to the technical field of die-casting forming, in particular to a die-casting pouring gate for solving shrinkage of an air hole in the middle of a multi-cylinder body, which comprises a feed port and a plurality of transverse pouring gates symmetrically arranged relative to a cavity of the formed cylinder body, and all the transverse pouring gates are communicated with the feed port. The cross sectional areas of the cross gates on the same side of the cylinder body cavity are sequentially reduced or sequentially increased; the main pouring gate is communicated with the transverse pouring gate and the feeding hole; the cross sectional area of the transverse pouring gate closest to the feeding hole is maximum; the main pouring gate is in a wave shape, each fork of the main pouring gate is connected with the transverse pouring gate, and the discharging direction of the main pouring gate at the fork position faces the transverse pouring gate. The scheme is used for solving the problem that the thick wall plate in the middle of the multi-cylinder body is prone to generating air holes and shrinkage cavities.

Description

Technical Field

[0001] The utility model relates to the technical field of die-casting forming, in particular to a die-casting runner for solving the problems of air holes and shrinkage holes in the middle of a multi-cylinder cylinder block. Background Art

[0002] The engine cylinder block, as the cornerstone of the power core, its manufacturing quality is directly related to the performance of the engine and even the whole vehicle. The density and mechanical strength of the cylinder block are not only the cornerstone of the efficient operation of the engine, but also the key indicators to measure the life and reliability of the engine. However, the complex internal structure of the cylinder block, significant wall thickness differences, and the dense heat dissipation rib design together pose insurmountable challenges in the casting process, easily inducing various casting defects and severely restricting the improvement of engine performance.

[0003] Taking the cylinder block of a four-cylinder engine as an example, the traditional casting process often adopts a single-sided feeding method. For example, the single-sided pouring system disclosed in the attached drawing of the patent publication No. CN208811031U "A bilateral pouring type pouring system for an engine cylinder block" can achieve initial forming, but product defects occur frequently and it is difficult to meet the strict requirements of modern engines for the quality of the cylinder block. Therefore, industry experts have explored the bilateral synchronous pouring technology, that is, the solution shown in the attached drawing of this published patent, intending to overcome the limitations of single-sided pouring through balanced material distribution and improve the casting quality. Figure 1 However, even with bilateral synchronous pouring, it is still difficult to overcome the casting problem of the wall thickness plate in the center of the cylinder block. This wall thickness plate not only bears the heavy responsibility of separating multiple cylinders, but also due to its structural characteristics - large thickness, central position, and holes in different directions - it is impossible to set up an effective exhaust channel at the wall thickness plate in the traditional process. In addition, the depth of the wall thickness plate is relatively large. Even under the condition of bilateral pouring, air holes and shrinkage holes still generally exist after casting, seriously affecting the density and mechanical properties of the cylinder block, becoming a bottleneck restricting the development of the die-casting forming technology of the cylinder block and also a problem that the current industry urgently needs to solve. Figure 2

[0004] Summary of the Utility Model

[0005] The utility model aims to provide a die-casting runner for solving the air holes and shrinkage holes in the middle of a multi-cylinder cylinder block, so as to solve the problem that air holes and shrinkage holes are likely to occur in the wall thickness plate in the middle of the multi-cylinder cylinder block.

[0006] To achieve the above purpose, the utility model adopts the following technical scheme:

[0007] A die-casting runner for solving the air holes and shrinkage holes in the middle of a multi-cylinder cylinder block includes a feeding port and a plurality of cross runners symmetrically arranged with respect to the cavity of the cylinder block to be formed. All cross runners are communicated with the feeding port, and the cross-sectional areas of the cross runners on the same side of the cylinder block cavity decrease or increase in sequence. ​​

[0008] The principle and advantages of this solution are as follows: The inventor studied the existing double-sided gating method and found that due to the fast flow velocity of the molten metal in the runner, the molten metal in the runner will quickly fill the cylinder cavity to improve production efficiency. However, when filling quickly, the molten metal on the left and right sides of each cylinder quickly converges towards the middle, especially towards the bottom area of the wall-thickness plate, blocking the gas discharge path in the cavity where the wall-thickness plate is located. Especially for the case where the wall-thickness plate has a large wall thickness and a deep depth, the gas that cannot be discharged will eventually accumulate in the area of the wall-thickness plate where the molten metal fills later, causing porosity and shrinkage in the wall-thickness plate.

[0009] In this solution, through the design of the cross-sectional area of the runner, the cross-sectional area of the runner closer to the feed inlet is made larger, so that the discharge flow rate of the runner closer to the feed inlet is the largest. Thus, when the cylinder is formed, the filling method of the cylinder cavity is sequential filling, that is, the cavity where the cylinder closer to the feed inlet side is filled first, and the subsequent cylinders are filled in sequence. This ensures that during the casting feeding process, the gas discharge path in the cavity is not blocked. When the gas can be discharged in time, the situation of porosity and shrinkage on the wall-thickness plate at the wall-thickness position is greatly reduced or even avoided.

[0010] Preferably, as an improvement, it further includes a main runner connecting the runner and the feed inlet, and the cross-sectional area of the runner closest to the feed inlet is the largest.

[0011] Preferably, as an improvement, the main runner is in a wavy shape, and each fork of the main runner is connected to a runner. The discharge direction of the main runner at the fork position faces the runner, so that the molten metal at the fork position on the main runner will preferentially enter the runner, ensuring that the runner closer to the feed inlet has a greater flow rate. With a large flow rate and a large cross-section, the pouring pressure at the ingate of each runner is made to tend to be consistent.

[0012] Preferably, as an improvement, the main runner is in a stepped shape along the discharge extension direction. Each step starts from the fork position, and the step is set such that the length and width of the cross-sectional width of the step farther away from the feed inlet gradually become smaller. In this solution, by setting steps at the fork, each step forms an obstruction to the molten metal, so that more molten metal preferentially flows towards the runner connected to the fork, ensuring sequential filling of the cavity for casting forming.

[0013] Preferably, as an improvement, the wavy main runner includes a primary main runner, a secondary main runner... an N-level main runner. Except for the primary main runner, the remaining main runners all have corners to reduce vortex gas entrainment.

[0014] Preferably, as an improvement, one end of the runner communicating with the main runner is in a necked-down structure, and the discharging end of the runner presents an outward-expanding structure. The outward-expanding discharging end of the runner approaches the adjacent runner, so that when the runner discharges, the molten metal can diffuse in the outward-expanding direction, and the diffusion direction makes the discharges of two adjacent runners tend to approach each other, so that the wall-thick plate located between the adjacent runners can be preferentially filled, effectively avoiding the gas entrapment problem caused by the lagging filling of the wall-thick plate, significantly promoting the timely discharge of gas, and further greatly reducing the generation of air holes and shrinkage cavities after the casting is formed.

[0015] Preferably, as an improvement, the runner is in a V shape with an angle greater than 90°. A feeding supplement area is arranged on the side of the ingate of the runner. The feeding supplement area is in a gradually changing wedge-shaped structure. The feeding supplement area transitions from the V-shaped corner of the runner to the discharging end close to the ingate, and one side of the feeding supplement area close to the discharging end of the ingate is also in transitional connection with the ingate.

[0016] Beneficial effects: In this solution, the cross-section of the feeding supplement area is designed as a gradually changing wedge-shaped structure, so that the feeding supplement area preheats the molten metal of the ingate, avoiding the situation that the molten metal is cooled due to the too long size of the ingate of the V-shaped structure of the runner, helping to maintain the heat flow temperature at the discharging end of the ingate, preventing rapid cooling, and at the same time helping to boost feeding and supplement, effectively suppressing the generation of shrinkage cavity defects, and improving the quality and mechanical properties of the casting.

[0017] Preferably, as an improvement, the ingate of the runner is inclined towards the end face of the cavity, and the inclination angle is consistent with the inclination angle of the cavity wall opposite to the discharging end of the ingate, so that the molten metal flowing out of the ingate can quickly move along the cavity structure, helping to improve the forming efficiency.

[0018] Preferably, as an improvement, the number of runners on the same side is one less than the number of cylinders of the cylinder block to be formed, so that the cylinder farthest from the feeding port does not have a corresponding runner, ensuring that the cavity of the cylinder farthest from the feeding port is filled with molten metal last, thus avoiding the situation that when a negative pressure suction exhaust passage is arranged at the edge of the cylinder block, the negative pressure sucks away the molten metal closest to the inside of the cylinder cavity and blocks the exhaust passage, helping to further reduce the probability of the generation of air holes and shrinkage cavities and improving the quality of the cylinder block after casting.

[0019] Preferably, as an improvement, the connection line of the ingates of the pair of runners with the largest cross-sectional area covers the wall-thick plate at the outermost edge of the cylinder block, so that the cavity where the wall-thick plate at the outermost edge is located can be filled earlier, greatly reducing or even avoiding the situation of air holes and shrinkage cavities caused by the gas staying here. Description of the Drawings

[0020] Figure 1 It is a three-dimensional structure diagram when the embodiment of the present utility model is applied.

[0021] Figure 2 is Figure 1 The three-dimensional structure diagram after adjusting the perspective.

[0022] Figure 3 is Figure 2 the top view of

[0023] Figure 4 is Figure 3 the A-A cross-sectional view in

[0024] Figure 5 is Figure 2 the front view of

[0025] Figure 6 is Figure 1 the three-dimensional structure diagram when only the runner and exhaust passage are shown without showing the cylinder block in

[0026] Figure 7 is Figure 6 the three-dimensional structure diagram after adjusting the perspective (the arrow direction in the figure indicates the negative pressure suction direction).

[0027] Figure 8 is Figure 6 the three-dimensional structure diagram of the die-casting runner for solving the shrinkage cavity of the middle air hole of the multi-cylinder block in this embodiment, that is

[0028] Figure 9 is Figure 8 the three-dimensional structure diagram after adjusting the perspective.

[0029] Figure 10 is Figure 9 the top view.

[0030] Figure 11 is Figure 9 the right view of

[0031] Figure 12 is Figure 9 the front view of

[0032] Figures 13 - 20 the schematic diagram of the metal liquid flow simulation during the die-casting pouring process of the solution of this embodiment (also called the mold flow analysis diagram).

[0033] Figure 13 is the schematic diagram when the metal liquid is split at the fork of the primary main runner (it can be clearly seen from the figure that when splitting at the fork, the material of the primary main runner preferentially flows to the cross runner connected to the fork position).

[0034] Figure 14Schematic diagram when the symmetric three pairs of runners discharge material (it can be clearly seen in the figure that when the material discharged between adjacent two runners diffuses, the discharged materials approach each other to facilitate the preferential filling of the thick-wall plate).

[0035] Figure 15 Schematic diagram when the molten metal flowing into the runner fills the thick-wall plate (it can be clearly seen in the figure that the thick-wall plate is preferentially filled, and the filling amount is the largest in the area where the lowest cylinder is located).

[0036] Figure 16 Schematic diagram when the area where the lowest cylinder is located is basically filled and the remaining cylinders are not filled (it can be clearly seen in the figure that the filling area of the cylinder regions from bottom to top becomes smaller and smaller, indicating that the cavity filling follows the order from bottom to top).

[0037] Figure 17 Schematic diagram when the remaining 2 cylinders are not filled (it can be seen in the figure that after the area where the lowest cylinder (closest to the feed inlet) is filled, the molten metal is extruded into the slag pocket area, and at this time, the area of the topmost cylinder (farthest from the feed inlet) has not been filled completely).

[0038] Figure 18 Schematic diagram when all cylinders are basically filled (it can be seen in the figure that after all cylinders are basically filled, the slag pocket / vent passage has not been filled, which is convenient for continuous feeding to allow the molten metal to perform feeding and compensation).

[0039] Figure 19 Schematic diagram of the process of molten metal entering the slag pocket area connected to the end of the cylinder block.

[0040] Figure 20 Schematic diagram when the vent passage is also filled with molten metal, and at this time, the pouring is completed. Detailed implementation method

[0041] The following is a further detailed description through specific implementation methods:

[0042] The reference numerals in the accompanying drawings of the specification include: feed inlet 1, main runner 2, primary main runner 21, secondary main runner 22, tertiary main runner 23, runner 3, connecting section 31, ingate section 32, ingate 321, feeding and compensation area 322, vent passage 4, slag pocket area 41, cylinder block 10, thick-wall plate 101.

[0043] The embodiment is basically as shown in the appendix Figures 1 to 20 shown.

[0044] A die-casting runner for solving the shrinkage cavity of the middle air hole of a multi-cylinder cylinder block, including a feed inlet 1 and a main runner 2 symmetrically arranged with respect to the feed inlet 1. The feed inlet 1 is located at the lowermost end and on the central axis of the cylinder block 10. The main runner 2 is symmetric about the central axis and extends from bottom to top. A plurality of cross runners 3 are arranged along the height direction of the main runner 2. All the cross runners 3 are communicated with the main runner 2. Along the height direction, the cross-sectional area of the lower cross runner 3 is larger. Specifically, the detailed design of the main runner 2 and the cross runner 3 is as follows:

[0045] I. Design of the main runner 2: The main runner 2 is designed in a wavy shape. A fork is formed at the connection of each wave. The cross runner 3 is communicated at the fork position. The cross runner 3 is located in the discharging direction of the main runner 2 on each waveform. The feed inlet 1 of the cross runner 3 faces the same direction as the discharging direction of the main runner 2 on each waveform. The feeding direction of the adjacent lower waveform is different from the discharging direction of the upper waveform and forms a V shape with the opening away from the cross runner 3, so as to ensure that the molten metal output on each waveform preferentially enters the adjacent cross runner 3, and ensure that the cross runner 3 closer to the feed inlet 1 has a larger flow rate.

[0046] Secondly, in order to ensure the flow rate shunted in each waveform, the discharging center line of the upper waveform is directly opposite to the feeding middle part of the lower waveform, so as to ensure that a certain amount of molten metal can enter the lower waveform when impacting the corner of the lower waveform and the cross runner 3.

[0047] To increase the tendency of the molten metal to flow towards the cross runner 3 and ensure the sequential filling of the cavity, the main runner 2 is arranged in a stepped shape along the discharging direction. Each step starts from the fork, that is, each step corresponds to a waveform. The length and width of the cross-section of the step away from the feed inlet 1 gradually decrease. In this embodiment, the number of cross runners 3 is three pairs, and the processed cylinder block 10 has four cylinders (including 5 wall thickness plates 101 in the middle). The wavy main runner 2 is divided into a primary main runner 21, a secondary main runner 22 and a tertiary main runner 23. Except for the primary main runner 21, the other two levels of main runners 2 are both designed with corners to reduce the eddy current and air entrainment, thereby reducing the formation of air holes / shrinkage cavities.

[0048] II. Design of the runner 3: The runner 3 itself is in a V shape with an angle greater than 90°. The runner 3 includes a connecting section 31 parallel to the main runner 2 and a gate section 32 inclined towards the end face of the cavity of the cylinder block 10. The connecting section 31 and the gate section 32 are connected in a transitional manner. The gate section 32 and the connecting section 31 form a V shape with an angle greater than 90°. At the connection between the runner 3 and the main runner 2, a necking structure is adopted, and the discharging end, that is, the gate section 32, gradually expands outward, and the expanding direction points to the gate section 32 of the adjacent runner 3, so that the discharging of each gate 321 shows a tendency to spread and approach the adjacent runner 3, ensuring that the forming area of the thick wall plate 101 can be injected with molten metal by adjacent runners 3 at the same time, thereby ensuring the pouring priority of the thick wall plate 101 area and greatly reducing or even avoiding the probability of gas holes / shrinkage holes at the position of the thick wall plate 101.

[0049] To further optimize the runner structure, a gradually changing wedge-shaped structure feeding compensation area 322 is provided on the outer side of the gate section 32 facing the cylinder block 10, so as to prevent the molten metal from cooling too quickly in the gate section 32. At the same time, the feeding compensation area 322 makes the overall cross-sectional area of the gate section 32 change from large to small, and then suddenly shrink at the discharging end, which helps with pressure feeding and compensation.

[0050] The inclination angle of the gate section 32 matches the inclination angle of the cavity wall. The end gate 321 of the gate section 32 is inclined towards the middle of the cavity end face.

[0051] The number of runners 3 is one pair less than the number of cylinders of the cylinder block 10, ensuring that the cylinder cavity farthest from the feeding port 1 is filled last, and avoiding blockage of the exhaust passage 4.

[0052] To ensure that the cylinder cavity part closest to the feeding port 1 is filled, and to ensure the priority filling of the thick wall plate 101 in the middle of this end, in this embodiment, the connection line of the gates 321 of the pair of runners 3 with the largest cross-sectional area covers the thick wall plate 101 at the outermost edge of the cylinder block 10, ensuring the priority filling of the outermost thick wall plate 101 area and reducing gas retention.

[0053] The middle pair of runners 3 is located between adjacent thick wall plates 101, and the pair of runners 3 with the smallest cross-sectional area is close to the penultimate thick wall plate 101.

[0054] This embodiment also provides a die-casting gating method for solving the shrinkage porosity of the middle air holes in the multi-cylinder block product, which requires the use of the above-mentioned die-casting runner. When pouring the casting material into the cavity of the block 10, the multiple cylinders of the block 10 are arranged along the height direction, and the discharge flow rate of the same-side transverse runner 3 is controlled to change sequentially from bottom to top to ensure that the cavity of the block 10 is filled in sequence from bottom to top. When the block 10 is die-cast and formed, the exhaust passage 4 communicates with a plurality of slag pocket areas 41, and the slag pocket areas 41 are arranged at the bottom end or the end of the formed block 10 away from the runner. During the gating process of die-casting and forming, the exhaust passage 4 adopts negative pressure suction to improve the discharge speed and discharge volume of the gas in the cavity.

[0055] At the same time, when the same pair of transverse runners 3 are gating, due to the wave design and step design of the main runner 2 and the outward expansion structure design of the transverse runner 3, after the metal of the same pair of transverse runners 3 is heated, the molten metal preferentially converges at the wall thickness plate 101, and then converges in the bottom area connected to the wall thickness plate 101, so as to ensure that the wall thickness plate 101 area is filled before the bottom area, ensure that the gas in the wall thickness plate 101 can be discharged in time, greatly reduce or even avoid the generation of air holes or shrinkage porosity in the wall thickness plate 101, ensure the fatality and mechanical properties of the block 10, and break through the bottleneck that the performance of the block 10 cannot be improved after die-casting.

[0056] The above are only the embodiments of the present invention. Specific technical solutions and / or common knowledge such as characteristics well known in the art are not described in detail here. It should be noted that for those skilled in the art, without departing from the technical solution of the present invention, several deformations and improvements can still be made, and these should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent. The protection scope required by this application should be subject to the content of its claims, and the specific implementation manners described in the specification can be used to interpret the content of the claims.

Claims

1. A die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body, comprising a feed port and a plurality of runners symmetrically arranged about the mold cavity of the formed cylinder body, all of which are connected to the feed port, and characterized in that: The cross-sectional areas of the runners located on the same side of the cylinder cavity gradually decrease or increase.

2. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder cylinder body according to claim 1 is characterized in that: It also includes a main runner connecting the cross runner and the feed port, and the cross runner closest to the feed port has the largest cross-sectional area.

3. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder cylinder body according to claim 2 is characterized in that: The main runner is wavy in shape, and each fork of the main runner is connected to a cross runner, and the discharge direction of the main runner at the fork is toward the cross runner.

4. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to claim 3 is characterized in that: The main runner is stepped along the direction of material discharge, each step starts from a fork position, and the steps are arranged so that the length and width of the cross-sectional width of the step farther away from the feed port gradually decrease.

5. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to claim 3 is characterized in that: The wavy main runner includes a primary main runner, a secondary main runner ... N-level main runners, and except for the primary main runner, the remaining main runners all have corners.

6. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to claim 3, characterized in that: The end of the runner communicating with the main runner is in a necking structure, and the end of the runner discharging material is in an outward expansion structure, and the outward expansion end of the runner discharging material is close to the runner on the adjacent side.

7. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to claim 6, characterized in that: The runner is V-shaped with an angle greater than 90°, and a shrinkage compensation area is provided on the side of the inner gate of the runner, and the shrinkage compensation area is in a gradually changing wedge-shaped structure.

8. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to claim 7, characterized in that: The ingate of the runner is inclined toward the end face of the cavity, and the inclination angle is consistent with the inclination angle of the cavity wall facing the discharge end of the ingate.

9. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to any one of claims 1 to 8, characterized in that: The number of runners located on the same side is one less than the number of cylinders of the molded cylinder body.

10. The die-casting runner for solving the problem of shrinkage of the middle pores in a multi-cylinder body according to any one of claims 1 to 8, characterized in that: The connecting line of the gates of a pair of horizontal runners with the largest cross-sectional area covers the thick wall plate at the outermost edge of the cylinder body.

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