A pressure feeding process and system for casting a V-shaped cylinder low-pressure core with a double-riser liquid pipe.

Abstract

This invention relates to a gravity-feeding process and system for low-pressure core casting of a V-shaped cylinder with double-riser liquid pipes. The system includes a pouring riser, an inner gate, a gate, double-riser liquid pipes, and a push-plate mechanism. The gate is divided into a left gate and a right gate. The double-riser liquid pipes are a left-side pouring riser and a right-side pouring riser. The molten aluminum rising in the double-riser liquid pipes will collect in the sandbag cavity of the V-shaped cylinder. The inner gate is located at the connection between the top of the double-riser liquid pipes and the pouring riser. During pouring, the left and right pouring riser pipes are poured simultaneously. The push-plate mechanism consists of a fixed cylinder and a plate. After pouring, the fixed cylinder pushes the plate into place, sealing the inner gate. The robot flips the sandbag containing molten aluminum, and gravity-feeding solidifies the mixture. This invention can reduce temperature loss during the aluminum filling process, prevent the formation of cold air gaps, and ensure that the mechanical properties of the cylinder crankcase bearing seat meet the technical requirements.

Description

Technical Field

[0001] This invention relates to the field of V-type engine block development and production, and to a pressure compensation process and system for casting a V-type cylinder block low-pressure core with a double-riser manifold. Background Technology

[0002] This invention relates to the development and production of automotive aluminum alloy V-type cast cylinder blocks. The production process involves sand mold core assembly, low-pressure casting, and pressure feeding, primarily applied to the production of low-pressure sand mold aluminum alloy V-type cast cylinder blocks. The V-type cylinder block length ranges from 380mm to 700mm. Current technologies all employ single-end liquid-lifting pipe casting, resulting in uneven aluminum temperature distribution after casting. This leads to localized hot spots and cold shuts in the cylinder block, significantly impacting engine life and stability, and in severe cases, causing oil and coolant leaks. Currently, there is virtually no published patent literature detailing casting technology for V-type aluminum alloy cast cylinder blocks. With the development and manufacturing of high-performance, high-power, complex internal V-type engine cylinder blocks, the quality of the cylinder block directly affects engine performance.

[0003] Currently, the internationally accepted casting processes for low-pressure sand-cast V-type aluminum alloy cylinder blocks are as follows: The first method uses bottom-pouring, where molten aluminum enters from the bearing seat and bottom surface, causing overheating at the bearing seat and resulting in coarse grains that cannot meet the mechanical performance requirements of the engine cylinder block; the second method uses aluminum entering from the left and right top surfaces, with the gate located at the front and rear end faces. For cylinder blocks with larger length dimensions, molten aluminum entering from the end faces causes inconsistent temperatures within the mold cavity. The flow of molten aluminum within the cavity causes temperature loss, with the molten aluminum at lower temperatures further away from the gate, forming a cold air gap. This does not cause leakage at room temperature, but leakage can occur at hot conditions due to the cold air gap.

[0004] The technical background of this invention is as follows: The technical requirements for a new type of large-size, complex internal cavity V-shaped aluminum alloy cylinder are as follows: water jacket pressure test: under an air pressure of 300 kPa, the leakage should not exceed 8 cm / min; cylinder main oil passage pressure test: under an air pressure of 400 kPa, the leakage should not exceed 10 cm / min. At the same time, the casting is required to be free from defects such as porosity, shrinkage cavities, cold shuts, and incomplete pouring. In order to meet the technical requirements of this product, a new casting process for the V-shaped cylinder was studied. It is necessary to ensure the feasibility of the casting process and the relative uniformity of the aluminum temperature in the cavity. Finally, the low-pressure core double-riser liquid pipe casting technology was determined.

[0005] Patent Document 1 (CN101298091A) discloses a low-pressure core-assembly casting process for V6 aluminum cylinder blocks of automobile engines. This process combines low-pressure casting and core assembly. First, a 3D model of the product is created. Based on the shape of the V6 aluminum cylinder block casting, the crankcase is positioned downwards, and molten aluminum is poured in through the crankcase baffle. The gate location and size are selected. Casting simulation software is used to simulate the casting process, analyze potential defects, and then a process design is developed based on the analysis results. Specifically, this includes: 1) core making; 2) assembling the sand cores into a sand core assembly; and 3) low-pressure casting. This invention can produce thin-walled, complex, and high-quality aluminum cylinder block castings by using flexible core-assembly methods according to different engine cylinder block shapes. It is suitable for mass production on automated production lines, thus offering advantages such as low cost, high efficiency, and high yield.

[0006] Patent document 2 (CN102091772A) discloses a low-pressure casting method for large castings, employing two or more crucible melting and holding furnaces, each with a riser pipe. The spacing between the melting and holding furnaces is adjusted according to the position of the sprue of the mold. During low-pressure casting, the mold is suspended on the low-pressure casting furnace, the low-pressure casting control device is activated, and molten aluminum enters the mold and is held under pressure according to the required process speed and pressure to complete the pouring.

[0007] Patent document 3 (CN102091772A) relates to an efficient low-pressure casting production method for aluminum alloy investment casting, characterized by the following steps: (1) placing aluminum ingots in a melting furnace, energizing the aluminum ingots to melt them at a melting temperature of 730±20℃ for 4-5 hours; (2) using a rotary degasser to perform degassing operations, introducing 99% pure argon gas for degassing and slag removal; (3) moving the melting furnace to a double-lifting-pipe low-pressure lifting machine. Below, two riser pipes are lowered and extended into the molten aluminum in the melting furnace. Two preheated mold shells are taken and placed on the double riser pipe low-pressure casting machine. The gates and riser pipes of the two mold shells are pressed together for casting. After casting, the pressure is automatically released, and the uncast mold shells are replaced. After casting, the liquid level in the melting furnace drops, and the melting furnace is pressure compensated. (4) The cast mold shells are deshelled using a shell-removing machine to obtain a casting blank with a gate. The gate is removed to obtain a complete casting. This can improve casting efficiency and ensure that the casting quality is high and reliable.

[0008] The aforementioned patent documents are not highly relevant to this application. Summary of the Invention

[0009] The purpose of this application is to design a double-lift liquid pipe casting process, in which aluminum is introduced from both the left and right sides simultaneously, ensuring uniform temperature of molten aluminum in the sand bag and achieving sequential solidification, thereby producing a high-quality V-shaped aluminum alloy cylinder body. This provides certain guidance for the development and production of low-pressure sand mold V-shaped aluminum alloy casting cylinder bodies.

[0010] The process of this invention can effectively solve the problem of the temperature field of aluminum liquid in sand core, improve the quality of V-shaped cylinder products, and provide a pressure feeding process and system for low-pressure core assembly and double-riser liquid pipe casting of V-shaped aluminum alloy cylinder.

[0011] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0012] To solve the above-mentioned technical problems, the present invention is implemented using the following technical solution:

[0013] A V-shaped cylinder low-pressure core double-riser liquid pipe pouring pressure compensation system includes a pouring riser 2, an inner gate 9, a gate, a double-riser liquid pipe, and a push-insertion plate mechanism;

[0014] The gate is divided into left gate 1-1 and right gate 1-2;

[0015] The dual riser pipes are two riser pipes, namely the left pouring riser pipe 6-1 and the right pouring riser pipe 6-2; the aluminum liquid rising in the dual riser pipes will collect in the sandbag cavity of the V-shaped cylinder.

[0016] The inner gate 9 is located at the connection between the top of the double-riser pipe and the pouring riser;

[0017] The push-insertion plate mechanism consists of a fixed cylinder and an insert plate; after the pouring is completed, the fixed cylinder pushes the insert plate into place and seals the inner gate.

[0018] Furthermore, the positions of the left-side pouring riser pipe 6-1 and the right-side pouring riser pipe 6-2 are determined based on the dimensions between the left and right top surfaces of the V-shaped cylinder.

[0019] Furthermore, the ingate is a cylindrical structure. After the low-pressure pouring is completed, the fixed cylinder pushes the insert plate. The space for the insert plate is reserved at the sand core position. The insert plate is pushed into the reserved space to seal the cylindrical ingate and prevent the aluminum liquid in the cavity from overflowing.

[0020] Furthermore, the centerline of the insert plate coincides with the cylinder axis;

[0021] Furthermore, two sets of the push-insertion plate mechanism are provided.

[0022] A pressure-compensating process for casting a V-shaped cylinder low-pressure core assembly with a double-riser liquid pipe includes the following steps:

[0023] Step 1: Assemble the V-shaped cylinder core;

[0024] Step 2: Pour the liquid into the pipes simultaneously on the left and right sides.

[0025] Step 3: After the pouring is completed, the fixed cylinder 7 pushes the insert plate 8 into place to seal the inner gate;

[0026] Step 4: Turn the sandbag over to allow it to solidify.

[0027] Further, in step one, the sandbag assembly process involves combining the bottom core, front and rear end cores, left and right side cores, left and right tube cores, inner core of the large cover, and top cover core to form a V-shaped cylinder sandbag.

[0028] Furthermore, in step two, the robot picks up the sandbag, rotates it 180° for pouring, and pours simultaneously through the left and right pouring risers; aluminum is introduced from both sides at the same time to ensure that the molten aluminum in the sandbag has a uniform temperature and achieves sequential solidification.

[0029] Furthermore, after the pouring is completed in step three, the fixed cylinder pushes the insert plate into place to seal the inner gate; a double insert plate design and a double cylinder design are adopted to seal the inner gate.

[0030] Furthermore, in step four, the robot flips the sandbag 180° to allow for gravity-assisted shrinkage and solidification.

[0031] Compared with the prior art, the beneficial effects of the present invention are:

[0032] This invention can reduce temperature loss during the aluminum molten metal filling process, prevent the formation of cold air gaps, and at the same time ensure that the mechanical properties of the cylinder block crankcase bearing seat meet the technical requirements. Attached Figure Description

[0033] The invention will now be further described with reference to the accompanying drawings:

[0034] Figure 1 Diagram of the low-pressure core double-riser liquid pipe casting process system;

[0035] Figure 2 Front view of the low-pressure core double-riser liquid pipe casting process system;

[0036] Figure 3 Side view of the low-pressure core double-riser liquid pipe casting process system;

[0037] Figure 4 This is a schematic diagram of the sandbag after the core assembly is completed;

[0038] Figure 5 This is a schematic diagram of the V-shaped cylinder low-pressure core double-lift liquid pipe casting pressure compensation system of the present invention;

[0039] Figure 6 A schematic diagram of the gating system, riser, and ingate structure;

[0040] In the picture:

[0041] 1-1: Left gate;

[0042] 1-2: Right gate;

[0043] 2: Casting riser;

[0044] 3: Core-assembly sandbags;

[0045] 4: Crucible;

[0046] 5: Furnace lid;

[0047] 6-1: Left-side pouring riser pipe;

[0048] 6-2: Right-side pouring riser pipe;

[0049] 7: Fixed cylinder;

[0050] 8: Power strip;

[0051] 9: Inner gate. Detailed Implementation

[0052] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some, but not all, embodiments of this invention. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain this invention, and should not be construed as limiting the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. The embodiments of this invention will be described in detail below with reference to the accompanying drawings.

[0053] In the description of this invention, it should be understood that the terms "center", "longitudinal", "lateral", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the scope of protection of this invention.

[0054] The present invention will now be described in detail with reference to the accompanying drawings:

[0055] This invention provides an embodiment of a V-shaped cylinder low-pressure core double-riser liquid pipe low-pressure gating force compensation system; including risers, ingates, and gating gates. Figure 1 The various structures in the casting process are made using a low-pressure casting process and the internal gate is sealed. Then, the sandbag and casting are rotated 180° to achieve gravity feeding.

[0056] V-type cylinder low-pressure core double riser pipe low-pressure gating force compensation system, employing double-plate mechanism to seal the inner gate technology, the double-plate mechanism in Figure 1 As shown, it consists of a fixed cylinder and a gate plate; the double gate plate design and double cylinder design, these components realize the sealing of aluminum liquid after the double liquid riser pipe is poured, which is a necessary condition for gravity feeding by flipping 180°. The "double gate plate mechanism sealing ingate technology" is "the fixed cylinder pushes the gate plate into place and seals the ingate;" The ingate is a cylindrical structure. After the low-pressure pouring is completed, the fixed cylinder pushes the gate plate. The space reserved for the gate plate at the sand core position can push the gate plate into the reserved space to seal the cylindrical ingate and prevent the aluminum liquid in the cavity from overflowing.

[0057] This invention proposes a low-pressure casting pressure feeding system for V-type aluminum alloy cylinder blocks using a low-pressure sand mold. Taking the V8TD cylinder block as an example, the schematic diagram is as follows: Figure 1 , Figure 2 , Figure 3 ;

[0058] Figure 1 This is a schematic diagram of the state of the low-pressure casting process, showing the double riser pipes and the pusher plate mechanism. Figure 2 A front view showing the appearance of the low-pressure casting process; Figure 3 A side view showing the appearance of the low-pressure casting process;

[0059] Principle of the casting process:

[0060] Assemble the V-shaped cylinder cores to form Figure 4 The sandbag assembly is shown below. The bottom core, front and rear end cores, left and right side cores, left and right tube cores, inner core of the large cover, and top cover core are assembled to form a V-shaped cylinder sandbag. The robot picks up the sandbag, rotates it 180° for pouring, and pouring occurs simultaneously through the two riser pipes. The two riser pipes are the left pouring riser pipe 6-1 and the right pouring riser pipe 6-2. The positions of the left pouring riser pipe 6-1 and the right pouring riser pipe 6-2 are determined based on the dimensions between the left and right top surfaces of the V-shaped cylinder. The two riser pipes are not connected; the rising aluminum liquid in the riser pipes will collect within the sandbag cavity of the V-shaped cylinder. After pouring, the fixed cylinder pushes the insert plate into place, sealing the inner gate 9. The centerline of the insert plate coincides with the cylinder axis. The inner gate 9 is located at the connection between the top of the riser pipe and the riser, as shown in the diagram. Figure 5 , Figure 6 The location is shown in the image. The robot flips the sandbag 180° to allow it to solidify.

[0061] This invention provides an embodiment of a gravity-feeding process for a V-shaped cylinder low-pressure core double-lift liquid pipe casting system. A V-shaped cylinder double-lift liquid pipe casting system enables the casting of a V-shaped cylinder, with aluminum entering from both the left and right sides simultaneously to ensure uniform temperature of the molten aluminum in the sandbag and achieve sequential solidification. After the double-insertion plate mechanism seals the ingate, it prevents the molten aluminum from overflowing the cavity. Then, the sandbag filled with molten aluminum is flipped over for gravity-feeding.

[0062] The process flow is as follows: sandbag assembly completed - low-pressure pouring through double-lifting pipes - cylinder pushes the insert plate to seal the inner gate aluminum liquid - robot flips the sandbag with aluminum liquid 180° - gravity feeding and solidification.

[0063] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications, equivalent substitutions, and improvements made by those skilled in the art within the scope of the technology disclosed in the present invention, and within the spirit and principles of the present invention, should be included within the scope of protection of the present invention. Furthermore, all content not described in detail in this specification is prior art known to those skilled in the art.

Claims

1. A pressure-compensating process for casting a V-shaped cylinder low-pressure core assembly with a double-riser liquid pipe, characterized in that... The process is completed through a V-shaped cylinder low-pressure core double-riser liquid pipe pouring pressure compensation system, which includes a pouring riser, an inner gate, a gate, a double-riser liquid pipe, and a push-insertion plate mechanism. The gate is divided into a left gate and a right gate; The dual riser pipes are a left-side pouring riser pipe and a right-side pouring riser pipe; the molten aluminum rising in the dual riser pipes will collect in the sandbag cavity of the V-shaped cylinder. The inner gate is located at the connection between the top of the double riser pipe and the pouring riser. The push-insertion plate mechanism consists of a fixed cylinder and an insert plate; after the pouring is completed, the fixed cylinder pushes the insert plate into place and seals the inner gate. The ingate is a cylindrical structure. After the low-pressure pouring is completed, the fixed cylinder pushes the insert plate. The space for the insert plate is reserved at the sand core position. The insert plate is pushed into the reserved space to seal the cylindrical ingate and prevent the aluminum liquid in the cavity from overflowing. The process includes the following steps: Step 1: Assemble the V-shaped cylinder core; Step 2: Pour the liquid into the pipes simultaneously on the left and right sides. Step 3: After pouring is completed, fix the cylinder to push the insert plate into place and seal the inner gate; Step 4: Turn the sandbag over to allow it to solidify; In step one, the sandbag assembly process involves combining the bottom core, front and rear end cores, left and right side cores, left and right tube cores, inner core of the large cover, and top cover core to form a V-shaped cylinder sandbag. In step two, the robot picks up the sandbag, rotates it 180° for pouring, and pours simultaneously through the left and right pouring risers; aluminum is introduced from both sides at the same time to ensure that the molten aluminum in the sandbag is at a uniform temperature and solidifies sequentially. After the pouring is completed in step three, the fixed cylinder pushes the insert plate into place to seal the inner gate; a double insert plate design and a double cylinder design are adopted to seal the inner gate. In step four, the robot flips the sandbag 180° to allow for gravity-assisted shrinkage and solidification.

2. The pressure-compensating process for low-pressure core assembly of a V-shaped cylinder as described in claim 1, characterized in that: The positions of the left and right pouring riser pipes are determined based on the dimensions between the left and right top surfaces of the V-shaped cylinder.

3. The pressure feeding process for casting a V-shaped cylinder low-pressure core assembly with double-riser liquid pipes according to claim 1, characterized in that: The centerline of the insert plate coincides with the cylinder axis.

4. The pressure feeding process for casting a V-shaped cylinder low-pressure core assembly with double-riser liquid pipes according to claim 1, characterized in that: Two sets of the push-insert plate mechanism are provided.

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