Gating system for the body of a large diesel engine with slag removal structure

Abstract

A large diesel engine fuselage casting system with a slag removal structure is provided, belonging to the field of diesel engine production technology. It includes a pouring cup, the water outlet of the pouring cup is connected to the casting mold through a straight runner, a cross runner, and an ingrown runner in sequence; it includes a pouring cup body; a basic insulation layer is laid on the bottom surface of the inner part of the pouring cup body, and an insulating water outlet is provided at both ends of the inner part of the pouring cup body. An iron liquid collection tank is provided on the outer periphery of the insulating water outlet, and a slag retaining platform is formed on the upper part of the insulating water outlet; a slag retaining ring is provided around the insulating water outlet; a plug removal device is provided on the side wall of the pouring cup body; a vibration device is fixed to the middle of the outer side of the bottom of the pouring cup body; the cross runner is a slag shielding and collecting runner structure with a height-to-width ratio greater than 1, the cross runner is connected to the ingrown runner through an iron liquid filtering device, the ingrown runner is a cylindrical structure that gradually changes to an open flat shape, and an iron liquid closed flow limiting structure is provided between the parting surfaces of the casting mold. This structure reduces slag and other foreign matter in the iron liquid, and avoids slag inclusion and inclusion defects after the casting is formed.

Description

Technical Field

[0001] The invention belongs to the technical field of diesel engine production, and in particular relates to a large diesel engine body casting system with a slag removal structure. Background Art

[0002] Diesel engine frames generally include L-type and V-type. Due to the difference in the structure of large diesel engine frames, the pouring positions of L-type and V-type frames are different during casting. The pouring position of L-type frame can be placed with the cylinder hole facing down or with the cylinder hole facing sideways. Figure 31 、 Figure 32 As shown, the V-type generally adopts the method of placing the cylinder hole face down, such as Figure 33 shown.

[0003] The fuselage pouring system is the channel that introduces qualified molten metal into the mold. The scientific and reasonable design of the pouring system has a very important impact on the smooth filling of the molten metal. The smooth flow of the molten metal plays a decisive role in the distribution of the molten iron's temperature field and the change in the surface area in contact with air. The less stable the molten iron flow is, and even when it sprays, the surface area of the molten iron in contact with air increases, and the degree of oxidation of the molten iron increases. The more elements such as iron, manganese, silicon, and magnesium in the molten iron form oxides with oxygen in the air, and these oxides are the main components of secondary slag. In addition, due to the increase in heat dissipation area, the molten iron dissipates heat faster, and the molten iron temperature drops significantly. The lower the molten iron temperature, the more oxides are generated. Therefore, ensuring the smooth filling of the molten iron is a key consideration in the design of the pouring system. The rationality of the pouring system is crucial to the quality of the diesel engine fuselage.

[0004] There are three general methods for casting large diesel engine fuselages: bottom pouring, center pouring, and step pouring. Bottom pouring generally fills the mold smoothly, but the temperature of the upper molten iron is lower; center pouring has a certain turbulence in the molten iron, but the upper temperature drops less; for diesel engine fuselage castings with larger height dimensions, considering the temperature drop during the filling process, one or a group of gates are generally added at a certain position on the upper part to add a certain amount of hot molten iron to the higher position of the casting, which is called step pouring. In step pouring, the upper molten iron and the lower molten iron will collide, which is prone to turbulence. Center pouring, bottom pouring, and step pouring are as follows: Figure 34 、 Figure 35 、 Figure 36 The pouring method has a significant impact on the stable filling of molten iron into the mold, the temperature field distribution of the mold, and the discharge of slag gas.

[0005] The amount of molten iron required to cast a large diesel engine fuselage is large, generally weighing over twenty tons, and some fuselages can weigh over forty tons. In order to effectively control parameters such as the temperature of the molten iron, large diesel engine fuselages generally use a quantitative or semi-quantitative pouring cup to introduce the molten iron into the mold. The pouring cup is the first checkpoint for the molten iron to enter the mold, and is very important for temperature control and purification of the molten iron. The quantitative pouring cup is a large, high-temperature-resistant container that is used to place all the molten iron for pouring the fuselage. The molten iron undergoes a series of standing and temperature measurement operations in the pouring cup before entering the mold. The semi-quantitative pouring cup is a smaller, high-temperature-resistant container that is used to fill the pouring cup with molten iron and then enter the mold after the temperature reaches the required level. At the same time, the ladle continues to pour molten iron into the pouring cup until all the molten iron has flowed out. Quantitative and semi-quantitative pouring cups each have their own characteristics. The semi-quantitative pouring cup is small in size and capacity, making it easy to build and lift. In addition, since the semi-quantitative pouring cup does not have a resting period, the molten iron dissipates little heat and cools down slowly. However, the semi-quantitative pouring cup only measures the temperature of a portion of the molten iron, making it impossible to accurately measure the temperature of the entire molten iron, making temperature control difficult. In addition, the semi-quantitative pouring cup cannot allow the molten iron to rest, which is not conducive to the floating and removal of slag and gas. Although the quantitative pouring cup is large in size and there is a certain amount of heat loss in the molten iron, it facilitates the molten iron to rest, which is conducive to the floating and removal of slag and gas, and also facilitates the precise control of the pouring temperature.

[0006] The sprue for large diesel engine fuselages is typically cylindrical. The sprue directs molten iron from the pouring cup into the pouring plane of the fuselage, serving as the second channel for the molten iron to enter the mold. Within the sprue, pressure heads vary at different heights. As the height decreases, the molten iron pressure increases. This constant pressure head ensures that the molten iron can fill the mold and form the fuselage casting. Therefore, properly designing parameters such as sprue height is crucial to avoiding defects such as under-casting, incomplete dimensions and shape, cold shuts, and air holes.

[0007] The runner is typically trapezoidal or cylindrical, connected to the sprue at the top and the ingrown at the bottom. It's a crucial intermediate step for molten iron to enter the mold. Generally, the pressure within runners at the same height is essentially the same. The runner's size, shape, and location significantly impact stable molten iron filling and its slag-blocking function.

[0008] The ingrowth of a large diesel engine is the last gateway for the molten iron to enter the casting mold. One end of the ingrowth is connected to the cross runner and the other end is connected to the casting. The form and arrangement of the ingrowth have a great influence on the stability of the molten iron filling and the uniformity of the molten iron distribution in the mold. The components of the fuselage casting system are as follows: Figure 37-Figure 38 shown.

[0009] Large diesel engine bodies generally utilize a stepped, closed or semi-closed pouring system, often employing a semi-quantitative pouring cup. For example, a large diesel engine body features a V-type, 20-cylinder design with a 60° cylinder bore angle. The overall dimensions are 5400×1500×1400mm, a 310mm diameter, a 490mm center-to-center distance between the bores, and a 90mm offset between the bores in rows A and B. The thinnest wall thickness is 20mm, while the thickest is 150mm. The main wall thicknesses are: 20mm around the bore and crankcase, 110mm at the free and output ends, 120mm at the crankshaft bearings, 100mm at the intermediate gear, and 120mm at the base plate. The body weighs 26 tons. The cylinders face downward, the mold utilizes an upper, middle, and lower parting system, and the core assembly process is employed. The pouring system adopts a stepped pouring system, that is, after the molten iron enters the pouring cup, the lower pouring system is opened first, and the molten iron enters the sprue, buffer mold, sub-sprue, cross runner, ingode, and then enters the mold. When the molten iron rises to about two-thirds of the fuselage, the upper pouring system is opened, and the molten iron passes through the sprue, cross runner, and ingode into the upper part of the fuselage to a predetermined height and fills the mold together with the original molten iron until it is full. Figure 38 The semi-quantitative pouring cup only measures the temperature of a portion of the molten iron, and the temperature of the entire molten iron cannot be accurately measured, making temperature control difficult. In addition, the semi-quantitative pouring cup cannot allow the molten iron to remain stationary, which is not conducive to the floating and removal of slag and gas.

[0010] This casting method often results in slag inclusions and other defects in the camshaft holes, observation windows, upper and lower cylinder bores, and air chambers of the diesel engine body during production. This can also lead to leaks in the cylinder bores due to inclusions. Statistics and analysis revealed that the overall distribution of slag and other defects in the engine body is random, with discrete distributions in different gears and cylinders of the camshaft and cylinder bores. However, comparative analysis also revealed a certain regularity in the defects at different heights, with defects generally located near the corners of the core or below the core's large flat surface. To address these issues, measures have been implemented to strengthen slag removal at various stages of the pre-furnace molten iron tapping and transfer process to reduce the amount of primary slag, control the casting temperature to reduce the formation of secondary slag, and perform local process corrections to eliminate defects through machining or grinding. However, verification has shown that these measures are ineffective, and defects still occur. The handling of slag and inclusions affected production nodes, delayed delivery times, and caused user complaints; more importantly, a large number of defects caused many fuselages to be scrapped. Some defects were discovered when the fuselage processing was about to be completed, resulting in huge scrap losses.

[0011] After comprehensively considering the roles of various factors including people, machines, materials, methods, and the environment, and combining the characteristics of fuselage defects, the original process conditions of the fuselage, and previous investigations and measures, it is believed that the fundamental reason for the frequent occurrence of slag and inclusion defects in the fuselage is the large amount of slag and other foreign matter mixed in the fuselage molten iron. Since the specific gravity of slag and inclusions is smaller than that of molten iron, these slag and foreign matter will float up with the molten iron after entering the casting along with the molten iron. After the molten iron fills the casting, they will continue to float up. During the floating process, these slag and foreign matter will continue to gather and grow. When they float to the corners or large flat surfaces of the core, the slag and inclusions will be blocked, and either the floating speed will be reduced or they will not be able to float up, resulting in the slag and inclusions being retained in the casting, exposing various inclusion defects when cleaning or processing the fuselage casting. This is related to the form of the casting system, the proportion of each team member, and the lack of slag blocking function of the casting system. Therefore, the body casting system directly affects the stability of molten iron filling and has a very important impact on the generation of secondary slag; more importantly, the casting system's slag blocking and shielding effects are insufficient, resulting in a large amount of primary slag and foreign matter entering the mold.

[0012] Based on the above defects, it is necessary to propose improvements. Summary of the Invention

[0013] The technical problem solved by the present invention is to provide a large diesel engine fuselage casting system with a slag removal structure. The present invention designs a dynamic slag blocking device, a plug pulling device, a molten iron collecting device, an active vibration slag structure in a quantitative pouring cup, and designs a bottom pouring open casting system, a horizontal runner with a slag collecting function, an open variable diameter inner runner, a portable multifunctional static pressure filter, and a molten iron closed flow limiting device, thereby reducing slag and other foreign matter in the molten iron, avoiding frequent slag inclusion and inclusion defects after casting, ensuring product quality, and reducing product scrap rate.

[0014] In order to achieve the above object, the technical solution adopted by the present invention is:

[0015] A large diesel engine body pouring system with a slag removal structure is a bottom-pouring open pouring system, comprising a pouring cup placed on the upper part of the mold, the water outlet of the pouring cup being connected to the inner cavity of the mold through a sprue, a runner, and an ingate in sequence;

[0016] The pouring cup is a quantitative pouring cup, comprising a pouring cup body, a vibration device, a plug removal device and a slag retaining ring;

[0017] A basic heat-insulating layer is laid on the inner bottom surface of the pouring cup body, and an insulating water inlet is provided at both ends of the inner bottom of the pouring cup body. An iron liquid collecting tank is provided on the outer bottom surface of the insulating water inlet, and the upper end of the insulating water inlet is higher than the iron liquid collecting tank to form a slag retaining platform;

[0018] A slag retaining ring is provided around the insulating water outlet; a plugging device is fixed on the side wall of the pouring cup body, and the plug head of the plugging device is tightly fitted with the water outlet of the insulating water outlet; the vibration device is fixed to the middle of the outer side of the bottom of the pouring cup body;

[0019] The cross runner is a slag shielding and collecting runner structure with an aspect ratio greater than 1. The cross runner is connected to the inner runner through a molten iron filtering device. The inner runner is a structure that gradually changes from a cylindrical shape to an open flat shape. A molten iron closed flow limiting structure is provided between the parting surfaces of the casting.

[0020] Among them, after the pouring cup body is welded and formed, a heat-resistant layer A with a thickness of 3mm to 5mm is first laid on the bottom surface of the interior thereof, and then a layer of formed refractory material B with a thickness of 60mm is laid, and then a layer of refractory material C with a thickness of 10mm to 20mm is laid, and finally a layer of refractory material D with a thickness of 30mm is laid to form a basic insulation layer. When laying the basic insulation layer, a nozzle position is reserved at each end;

[0021] Install the shaped nozzle refractory brick E at the center of the reserved nozzle position. The upper plane of the shaped nozzle refractory brick E is 40mm higher than the bottom plane of the molten iron collecting tank. Fill the refractory material C around the shaped nozzle refractory brick E so that it is flush with the shaped nozzle refractory brick E, thereby forming an insulated water nozzle; the shaped nozzle refractory brick E and the 40mm super-high refractory material C form a slag stop.

[0022] A layer of 30mm to 60mm thick refractory material C is laid on the inner surface of the molten iron collecting tank, with both sides of the refractory material C being inclined at an angle of 2° to 3° to the plane of the refractory material D), i.e., low in the middle and high on both sides; and then a layer of 30mm thick formed refractory material D is laid on top.

[0023] Furthermore, the vibration device includes a vibration base fixed to the middle of an outer side of the bottom of the pouring cup body, and a vibrator is fixed to the vibration base by fastening bolts.

[0024] Furthermore, the plug-pulling device includes a refractory plug-pulling head, a shaped refractory tube, a plug-pulling rod, a plug-pulling pressure rod and a plug-pulling bracket. The refractory plug-pulling head and the shaped refractory tube are installed on the plug-pulling rod in sequence and the upper and lower parts are locked with nuts; the middle part of the plug-pulling pressure rod is connected to the top of the plug-pulling bracket by bolt I, and the top of the plug-pulling rod and the end of the plug-pulling pressure rod are connected by bolt II.

[0025] Furthermore, the slag retaining ring includes a circular ring L made of φ8mm round steel welded and adapted to the outer periphery of the insulated water outlet. A layer of 3mm thick refractory material M1 is wrapped around the circular ring L, and then a layer of φ1mm fastening material N1 is wrapped in the opposite direction, and then a layer of 2mm refractory material M2 is wrapped on the fastening material N1 layer, and then a layer of φ1mm fastening material N2 is wrapped in the opposite direction; repeat the above steps to make the circular ring L thicker by another 5mm.

[0026] Furthermore, the slag shielding and collecting runner structure on the runner includes a plurality of slag shielding grooves evenly distributed on the inner wall of the runner, and a slag collecting bag provided at the end of the runner.

[0027] Furthermore, the molten iron filtering device includes a molten iron filter, a pre-filtration molten iron buffer zone is provided on the upper portion of the molten iron filter, and a post-filtration molten iron buffer zone is provided on the lower portion of the molten iron filter.

[0028] Furthermore, the ingrown channel includes a cylindrical ingrown channel straight tube, the ingrown channel straight tubes are connected by a cylindrical ingrown channel bend tube, the ingrown channel outlet is connected to the inner cavity of the casting mold through a special-shaped variable-section ingrown channel, the cross-sectional size of one end of the special-shaped variable-section ingrown channel is the same as that of the ingrown channel straight tube and the ingrown channel bend tube, and the cross-sectional size of the other end of the special-shaped variable-section ingrown channel is gradually enlarged to 1.5 to 3 times, and the end thereof is a rectangle with an aspect ratio of 3 to 8.

[0029] Furthermore, the casting mold includes an upper casting mold and a lower casting mold. A closed ring groove is provided on the parting surface of the lower casting mold within a range of 30-50 mm from the casting. A sealing strip with a diameter of φ3-φ10 mm is provided in the closed ring groove and is clamped between the upper casting mold and the lower casting mold. After the upper casting mold and the lower casting mold are combined, the parting gap is not greater than 3 mm. This structure forms a closed flow limiting structure for molten iron.

[0030] The advantages of the present invention compared with the prior art are:

[0031] 1. In this solution, a dynamic slag retaining ring is designed in the quantitative pouring cup, which ensures that a large amount of slag and inclusions in the upper layer of molten iron in the pouring cup are blocked outside the slag ring and eventually stay in the pouring cup instead of entering the sprue;

[0032] 2. In this solution, a multifunctional plug-pulling device is designed inside the quantitative pouring cup to achieve temperature control of the molten iron and high-temperature static effect of the molten iron;

[0033] 3. In this solution, a directional molten iron collection device is designed in the quantitative pouring cup, which reduces the amount of residual molten iron in the pouring cup. The weight of the residual molten iron is reduced from the original 1400kg to 200kg. The weight of molten iron per machine body is reduced by 1200kg, and the cost of each machine body is saved by more than 10,000 yuan;

[0034] 4. The pouring cup vibration device in this solution is used to vibrate the slag during the static stage of the molten iron, thereby improving the slag floating efficiency;

[0035] 5. This solution adopts a bottom pouring open casting system, which avoids the impact of the molten iron in the upper casting system on the molten iron in the lower casting system, ensures the smooth filling of the molten iron into the mold, and avoids the formation of secondary slag caused by turbulence. The open casting system avoids the turbulence caused by the molten iron injection in the inner gate generated by the semi-closed casting system of the original technology, ensures the stability of the molten iron entering the casting mold at the beginning, and reduces the generation of secondary slag.

[0036] 6. The horizontal runner with slag collection function in this solution uses the low specific gravity of slag to block and collect slag and inclusions in the molten iron entering the horizontal runner, thereby reducing the amount of slag entering the subsequent channels;

[0037] 7. In this solution, an open, variable-diameter ingrown is designed to reduce the molten iron filling velocity, thus avoiding or reducing the secondary slag generated by molten iron oxidation caused by excessive molten iron flow or even jetting. By arranging the ingrown on the same plane as the machine body, the impact of molten iron in the mold is avoided, the tendency of molten iron turbulence is reduced, and the generation of secondary slag in the molten iron is reduced.

[0038] 8. This solution designs a portable, multifunctional static pressure molten iron filter. It utilizes a static pressure head to physically filter the molten iron entering the ingrown channel, blocking foreign matter such as slag and inclusions at the filter input, thereby ensuring the purity of the molten iron at the output. This filter differs from other filtration methods in that it utilizes the inherent pressure head of the filter to actively fill the filter, eliminating the need for a filter disc float-prevention device above the filter. This makes it simpler and more efficient than existing filters, saving 10kg of molten iron per unit. Each unit can save over 200kg of molten iron.

[0039] 9. In this scheme, a molten iron sealing and flow limiting device is designed in the casting mold to seal the molten iron in a preset channel or path. On the one hand, it prevents the molten iron from entering the casting mold unexpectedly, effectively ensuring the filling of the mold with clean molten iron. On the other hand, it reduces the area of the seam around the casting and reduces the consumption of invalid molten iron. Each machine body can save about 500kg of molten iron. Moreover, the use of the molten iron sealing and flow limiting device also facilitates the cleaning of the machine body, reduces the workload of the machine body cleaning, and improves the efficiency of the machine body cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a structural schematic diagram of the present invention;

[0041] Figure 2 This is a top view of the structure of the pouring cup in the present invention;

[0042] Figure 3 For the present invention Figure 2AA structural diagram in the figure;

[0043] Figure 4 For the present invention Figure 2 BB-direction structure diagram;

[0044] Figure 5 It is a front view of the pouring cup of the present invention;

[0045] Figure 6 This is a front view of the vibration base of the present invention;

[0046] Figure 7 A top view of the vibration base of the present invention;

[0047] Figure 8 For the present invention Figure 7 Schematic diagram of CC cross-sectional structure;

[0048] Figure 9 For the present invention Figure 7 Schematic diagram of the D-direction structure;

[0049] Figure 10 This is a front view of the structure of the plug removal device of the present invention;

[0050] Figure 11 For the present invention Figure 10 Schematic diagram of EE cross-section structure;

[0051] Figure 12 For the present invention Figure 10 Schematic diagram of FF cross-sectional structure;

[0052] Figure 13 A top view of the structure of the plug removal device of the present invention;

[0053] Figure 14 This is a structural front view of the slag retaining ring in the present invention;

[0054] Figure 15 This is a top view of the structure of the slag retaining ring in the present invention;

[0055] Figure 16 For the present invention Figure 15 Schematic diagram of the GG cross-sectional structure;

[0056] Figure 17 This is a top view of the structure after the pouring cup is installed in the present invention;

[0057] Figure 18 For the present invention Figure 17 Schematic diagram of HH cross-sectional structure;

[0058] Figure 19 For the present invention Figure 17 Schematic diagram of II cross-section structure;

[0059] Figure 20 For the present invention Figure 17 Schematic diagram of the JJ cross-sectional structure;

[0060] Figure 21 Schematic diagram of the structure of the runner in the present invention;

[0061] Figure 22 For the present invention Figure 21 Schematic diagram of KK cross-sectional structure;

[0062] Figure 23 Schematic diagram of the structure of the molten iron filtering device in the present invention;

[0063] Figure 24 For the present invention Figure 23 LL cross-sectional structure diagram in;

[0064] Figure 25 Schematic diagram of the structure of the ingrown channel in the present invention;

[0065] Figure 26 For the present invention Figure 25 Schematic diagram of MM cross-sectional structure;

[0066] Figure 27 Schematic diagram of the structure of the casting mold in the present invention;

[0067] Figure 28 For the present invention Figure 27 Schematic diagram of the closed groove shown in the NN section;

[0068] Figure 29 For the present invention Figure 27 Schematic diagram of installing a closing strip in a closing groove shown in cross section NN;

[0069] Figure 30 For the present invention Figure 27 The schematic diagram after fusion is shown in the middle NN section;

[0070] Figure 31 A schematic diagram of an L-shaped diesel engine body with the cylinder bore facing downwards in the prior art;

[0071] Figure 32 It is a schematic diagram of the side view of the cylinder bore surface of an L-type diesel engine body in the prior art;

[0072] Figure 33 A schematic diagram of a V-type diesel engine body with the cylinder bore facing downwards in the prior art;

[0073] Figure 34 It is a schematic diagram of a diesel engine body cast using a center injection method in the prior art;

[0074] Figure 35It is a schematic diagram of a diesel engine body cast by bottom injection in the prior art;

[0075] Figure 36 A schematic diagram of a prior art diesel engine body using a top-up and bottom-injection casting structure;

[0076] Figure 37 Schematic diagram of the top and bottom pouring method for diesel engine body in the prior art Figure 1 ;

[0077] Figure 38 Schematic diagram of the top and bottom pouring method for diesel engine body in the prior art Figure 2 . DETAILED DESCRIPTION

[0078] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0079] It should be noted that, as used herein, the terms "comprise," "include," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the elements.

[0080] See also Figure 1-30 , details the embodiments of the present invention.

[0081] Embodiment: A large diesel engine body casting system with a slag removal structure is described in this embodiment using a 20-cylinder V-type diesel engine body as an example.

[0082] The pouring system is a bottom pouring open pouring system, see Figure 1 As shown, it includes a pouring cup 1 placed on the upper part of the mold, and the water outlet of the pouring cup 1 is connected to the inner cavity of the mold through a straight runner 2, a horizontal runner 3, and an inner runner 4 in sequence.

[0083] In this embodiment, the pouring cup 1 is a quantitative pouring cup, which includes a pouring cup body 1-1, a vibration device 1-2, a plug-pulling device 1-3 and a slag retaining ring 1-4.

[0084] The bottom surface of the pouring cup body 1-1 is paved with a basic heat insulation layer. Figure 2-5 As shown, after the pouring cup body 1-1 is welded and formed, a 3mm-5mm thick heat-resistant layer A1-1-1 is first laid on its inner bottom surface, followed by a 300×150×60mm thick formed refractory material B layer 1-1-2, a 10mm-20mm thick refractory material C layer 1-1-3, and finally a 300×150×30mm thick refractory material D layer 1-1-4 to form the basic insulation layer. When laying the basic insulation layer, a 300×300mm nozzle position is reserved at each end.

[0085] In this embodiment, the two ends of the bottom of the inner part of the pouring cup body 1-1 are provided with an insulating water inlet 1-1-5, and the outer bottom surface of the insulating water inlet 1-1-5 is provided with a molten iron collecting tank 1-1-7. The upper end of the insulating water inlet 1-1-5 is higher than the molten iron collecting tank 1-1-7 to form a slag blocking platform 1-1-8.

[0086] Production of insulating water inlet: Install the molded water inlet refractory brick E1-1-6 at the center of the reserved water inlet position. The upper plane of the molded water inlet refractory brick E1-1-6 is 40mm higher than the bottom plane of the molten iron collecting tank 1-1-7. Fill the surrounding area of the molded water inlet refractory brick E with refractory material C to make it flush with the molded water inlet refractory brick E1-1-6, thereby forming an insulating water inlet 1-1-5; the molded water inlet refractory brick E1-1-6 and the 40mm excess height of the filled refractory material C form a slag retaining platform 1-1-8.

[0087] Fabrication of the molten iron collection trough: A molten iron collection trough was constructed outside the 1000×700mm area at each end of the pouring cup. A 30mm-60mm-thick layer of refractory material C was laid on the inner surface of the molten iron collection trough 1-1-7, with both sides inclined at a 2°-3° angle to the plane of refractory material D1-1-4, with the center lower and the sides higher. A 30mm-thick layer of formed refractory material D was then laid on top. By designing a directional molten iron collection trough within the metered pouring cup, the amount of residual molten iron in the pouring cup was reduced from 1400kg to 200kg. This reduced the weight of molten iron per machine body by 1200kg, saving over 10,000 yuan per machine body.

[0088] Production of slag retaining platform: Use refractory material C to increase the nozzle area of 300×300mm by 40mm, and pay attention to the grinding treatment of the nozzle.

[0089] A slag-blocking ring 1-4 is provided around the insulating water inlet 1-1-5. Specifically, the slag-blocking ring 1-4 comprises a φ350mm circular ring L1-4-1 made of φ8mm round steel welded together and adapted to the outer periphery of the insulating water inlet 1-1-5. A layer of refractory material M1 layer 1-4-2 with a thickness of about 3mm is wound around the circular ring L1-4-1, and then a circle of φ1mm fastening material N1 layer 1-4-3 is wound in the opposite direction, and then a layer of 2mm refractory material M2 layer 1-4-4 is wound on the fastening material N1 layer 1-4-3, and then a circle of φ1mm fastening material N2 layer 1-4-5 is wound in the opposite direction; repeat the above steps to make the circular ring L1-4-1 thicker by another 5mm. The slag-blocking ring structure is shown in FIG. Figure 14-16 This dynamic slag ring ensures that a large amount of slag and inclusions in the upper layer of molten iron in the pouring cup will flow out of the slag ring into the pouring cup instead of entering the sprue.

[0090] A plug-pulling device 1-3 is fixed on the side wall of the pouring cup body 1-1, and the plug head of the plug-pulling device 1-3 fits tightly with the water outlet of the insulated water outlet 1-1-5. Specifically, the plug-pulling device 1-3 includes a refractory plug head 1-3-1, a formed refractory tube 1-3-2, a plug-pulling rod 1-3-3, a plug-pulling pressure rod 1-3-5 and a plug-pulling bracket 1-3-6. The φ22mm plug-pulling rod 1-3-3 is sequentially mounted with a refractory plug head 1-3-1 and a formed refractory tube 1-3-2, and the upper and lower parts are locked with M16 nuts 1-3-4; the middle part of the plug-pulling pressure rod 1-3-5 is connected to the top of the plug bracket 1-3-6 by bolt Ⅰ 1-3-8, and the top of the plug-pulling rod 1-3-3 and the end of the plug-pulling pressure rod 1-3-5 are connected with M10 bolt Ⅱ 1-3-7. See the structure of the plug-pulling device. Figure 10-13 The multifunctional plug-pulling device enables the temperature control of the molten iron and the high-temperature stabilization of the molten iron.

[0091] The vibration device 1-2 is fixed to the middle of the outer side of the bottom of the pouring cup body 1-1. Specifically, the vibration device 1-2 includes a vibration base 1-2-1 of φ100×120mm fixed to the middle of the outer side of the bottom of the pouring cup body 1-1. Figure 6-9 The vibrator 1-2-2 is fixed on the vibration base 1-2-1 by fastening bolts 1-2-3. Figure 18 The vibration device vibrates the slag during the static stage of the molten iron, which improves the floating efficiency of the slag.

[0092] In the above, the heat-resistant layer A used is a dense asbestos product, the formed refractory materials B and D, the nozzle refractory brick E is a high-alumina heat-resistant brick, the plug-shaped refractory tube, and the refractory plug head is a graphite product, which can be pre-ordered or purchased on the market. The refractory material C used is a mixture of homemade refractory cement, adhesive, zircon sand, additives, coatings, etc. in a certain proportion. The vibration device used is a construction vibration rod, which can be purchased on the market. The plug rod, plug pressure rod, and plug bracket used are all made of Q345, and the size and shape are achieved through independent welding and processing. Bolts, nuts, gaskets, etc. are standard parts and can be purchased. The slag ring L used is made of Q235 and is formed by self-welding. The fastener materials N, N1, and N2 are all made of Q235, and the size, shape, and function can be achieved through independent operation. Refractory material M1 is refractory asbestos rope, and M2 is refractory asbestos cloth, both of which can be purchased.

[0093] See Figure 17-20 As shown in the figure, install the pouring cup, plug removal device, slag retaining ring and vibration device:

[0094] First, dry the finished pouring cup, plug removal device, and slag retaining ring to ensure they are dry. Drying temperature: 300°C to 350°C, drying time: 3 to 4 hours.

[0095] Secondly, clean the floating sand and other foreign objects on the inner surface of the pouring cup to ensure that the pouring cup is clean.

[0096] Next, place the pouring cup on the mold on the fuselage, aligning the pouring cup outlet with the fuselage outlet.

[0097] Next, place a slag retaining ring around the nozzle, then install and fix the pouring bracket on the side of the pouring cup, and install the plug rod at the nozzle position so that the plug head on the plug rod fits tightly with the nozzle.

[0098] Connect the cork extraction rod and the cork extraction bracket with bolts.

[0099] Connect the front section of the corkscrew pressure rod and the upper end of the corkscrew rod with bolts.

[0100] Check that all components are working properly. Operate the pressure rod up and down to check if the pressure rod and the plug rod are stuck.

[0101] The cork extraction rod is supported and a counterweight is hung on the end, and the cork extraction device is in a standby state.

[0102] Install the vibration device head into the base of the pouring cup and tighten it with 3 fastening bolts.

[0103] Working process of pouring cup, plug removal device, slag retaining ring and vibration device:

[0104] The molten iron that meets the tapping temperature and has qualified chemical composition is spheroidized and inoculated.

[0105] The molten iron entering the ladle is cleaned of slag and then transported to the pouring site. Note that the transportation time should be less than 10 minutes.

[0106] After removing the slag again, quickly pour all the molten iron in the ladle into the quantitative pouring cup, then let the molten iron stand and turn on the vibration device at the same time. The molten iron standing time should be more than 3 minutes.

[0107] Measure the temperature of the molten iron. When the temperature of the molten iron in the pouring cup reaches the process requirements, turn off the vibrator and open the plug-pulling device. The molten iron enters the mold through the nozzle, sprue, runner and ingrown.

[0108] The slag retaining ring maintains consistent alignment with the liquid level from the moment the molten iron enters the pouring cup until it exits. Once the molten iron enters the pouring cup, the slag retaining ring rises with the molten iron due to buoyancy. When the molten iron is stationary, the slag retaining ring remains above the liquid level at the nozzle and cannot leave the nozzle due to the restriction of the plug removal mechanism.

[0109] During the static period, foreign matter such as oxides and slag collectors in the molten iron, due to their lower density than the molten iron, rises to the surface in large quantities. As the molten iron gradually leaves the pouring cup, the liquid level drops, and the slag retaining ring descends simultaneously. When the liquid level reaches the sump, the inclined surface within the pouring cup eliminates any remaining molten iron outside the sump. This significantly reduces the amount of molten iron remaining in the pouring cup, saving approximately 1,200 kg of molten iron per machine.

[0110] When the molten iron level drops to the slag retaining platform position, the slag retaining ring is located outside the slag retaining platform of the water inlet, and the oxides and inclusions on the surface of the surrounding molten iron are blocked outside the ring by the slag retaining ring. These oxides and inclusions are eventually retained in the residual molten iron in the pouring cup.

[0111] The above structure solves the problem of the lack of slag collection and blocking ability of the pouring cup, and the problem of excessive residual molten iron in the quantitative pouring cup of the fuselage, resulting in serious waste; the floating efficiency of the slag in the pouring cup is improved by combining the static passive slag and active slag of the pouring cup; and the secondary inclusion phenomenon caused by the turbulent flow of molten iron caused by the stepped pouring system of the fuselage is solved.

[0112] In this embodiment, the runner 3 is a slag shielding and collecting runner structure with an aspect ratio greater than 1. The slag shielding and collecting runner structure on the runner 3 includes a plurality of slag shielding grooves 3-1 evenly distributed on the inner wall of the runner 3, and a slag collecting bag 3-2 provided at the end of the runner 3. This structure makes full use of the principle that the specific gravity of slag is less than that of molten iron and that slag gradually floats up during the flow of molten iron, and blocks, separates and collects slag in the molten iron entering the runner. Figure 21-22The cross runner structure reduces the amount of slag entering the rear channel and solves the problem of excessive slag in the molten iron caused by the lack of slag action in the cross runner of the fuselage.

[0113] In this embodiment, the runner 3 is connected to the ingrow 4 through the molten iron filtering device 7 to purify the molten iron before entering the ingrow. The molten iron filtering device 7 adopts a static pressure head self-filling method, which has the characteristics of simple structure, high efficiency and convenience. Figure 23-24 . The molten iron filtering device 7 includes an molten iron filter 7-1, a pre-filtration molten iron buffer zone 7-2 is provided on the upper part of the molten iron filter 7-1, and a post-filtration molten iron buffer zone 7-3 is provided on the lower part of the molten iron filter 7-1. The molten iron filter is a porous, mesh-shaped refractory material and can be purchased. By designing a portable multifunctional static pressure filter, the static pressure head is used to physically filter the molten iron entering the inner pouring channel, and foreign matter such as slag and inclusions in the molten iron is blocked at the input end of the filter, thereby ensuring that the molten iron at the output end is pure. The difference between this filter and other filtering methods is that it is designed by actively filling the filter using the inherent pressure head of the machine body. There is no need to set a device above the filter to prevent the filter from floating up. It is simpler and more efficient than the original filter, saving 10kg of molten iron weight per piece, and each machine body can save more than 200kg of molten iron. In addition, this filter is designed to be portable and does not need to be fixed on the cross runner. Its positioning includes two methods: magnet or pin hole positioning, which is convenient for sharing with multiple products, improving the use effect of the filter, and realizing the purification of the molten iron entering the casting system. The slag and inclusions in the molten iron are filtered out of the casting mold to achieve the purpose of purifying the molten iron in the casting mold.

[0114] In this embodiment, the gate 4 is a cylindrical structure that gradually changes to an open flat structure. Figures 25-26 The ingrown channel 4 includes a cylindrical ingrown channel straight pipe 4-1, which is connected to each other by a cylindrical ingrown channel bend 4-2, and the outlet of the ingrown channel 4 is connected to the inner cavity of the mold through a special-shaped variable-section ingrown channel 4-3. The ingrown channel straight pipe 4-1, the ingrown channel bend 4-2 and the special-shaped variable-section ingrown channel 4-3 are all made of ceramic and can be customized or purchased.

[0115] The cross-sectional dimensions of one end of the special-shaped variable-section ingrown 4-3 are the same as those of the straight ingrown pipe 4-1 and the curved ingrown pipe 4-2. The cross-sectional dimensions of the other end of the special-shaped variable-section ingrown 4-3 are gradually enlarged to 1.5 to 3 times, and the end thereof is a rectangle with an aspect ratio of 3 to 8. This design has three advantages. First, the open design of the ingrown helps reduce the flow rate of the molten iron, facilitates the smooth filling of the mold by the molten iron, reduces the oxidation tendency of the molten iron, and reduces the probability of the generation of secondary oxidation slag of the molten iron. Second, the surface area of the flat ingrown ...

[0116] By designing an open, variable-diameter ingrown gate, the molten iron filling velocity is reduced, thus avoiding or reducing the secondary slag generated by molten iron oxidation caused by excessive molten iron flow or even jetting. By arranging the ingrown gate on the same plane as the machine body, the impact of molten iron in the mold is avoided, the tendency of molten iron turbulence is reduced, and the generation of secondary slag in the molten iron is reduced.

[0117] This embodiment also utilizes a bottom-pouring, open pouring system, which prevents the impact of molten iron in the upper pouring system on the lower pouring system, ensures smooth filling of the mold, and avoids the formation of secondary slag caused by turbulence. The open pouring system avoids the turbulence caused by molten iron ejection from the inner runner produced by the semi-enclosed pouring system of the previous technology, ensures the initial smooth entry of molten iron into the mold, and reduces the generation of secondary slag. This solves the problem of increased secondary slag caused by molten iron ejection due to improper design and distribution of the inner runner of the fuselage, as well as the problem of shrinkage at the runner position of the casting.

[0118] In this embodiment, refer to Figures 27-30 . A closed flow-limiting structure for molten iron is provided between the parting surfaces of the mold. The mold comprises an upper mold 6 and a lower mold 5. A closed annular groove 5-1 is provided on the parting surface of the lower mold 5 within a range of 30-50 mm from the casting. A sealing strip 8 with a diameter of φ3-φ10 mm is provided in the closed annular groove 5-1 and is sandwiched between the upper mold 6 and the lower mold 5. The parting gap between the upper mold 6 and the lower mold 5 is no more than 3 mm after the upper mold 6 and the lower mold 5 are combined. This structure forms a closed flow-limiting structure for molten iron. The closed flow-limiting device for molten iron can prevent molten iron from unexpectedly entering the mold and causing defects such as cold shut, iron beans, and insufficient pouring in the fuselage casting by designing a flow blocking groove for the path through which the molten iron flows during the filling and overflow processes. It can also prevent molten iron from entering the mold and the air outlet channel of the clay core, causing defects such as fire leakage, choking, suffocation, and air holes. At the same time, it can greatly reduce the skin seam area and skin seam thickness, save molten iron, and improve the fuselage process yield.

[0119] The molten iron sealing and flow limiting device confines the molten iron within a pre-set channel or path, effectively ensuring clean molten iron filling the mold and reducing the consumption of ineffective molten iron. Each machine can save approximately 500kg of molten iron. Furthermore, the use of the molten iron sealing device also facilitates machine cleaning, reducing the cleaning workload and improving cleaning efficiency.

[0120] Experimental testing:

[0121] The casting material used in this embodiment is QT400-15A ductile iron, and the smelting batching control is shown in Table 1. The main chemical composition control during the smelting process in the invention example is shown in Table 2. The pouring temperature, time and other parameters in the invention example are shown in Table 3.

[0122] Comparing the test results with the standard parameters of the main evaluation indicators of the present invention shows that the QT400-15A with different compositions mentioned above all meet the performance index requirements for this type of diesel engine fuselage. At the same time, the fuselage cast by the invention has a smooth surface and a dense internal structure. Slag inclusions and other defects no longer appear in the camshaft hole, observation window, upper and lower cylinder holes, air cavity, and other areas. There is no water leakage due to inclusions in the cylinder hole and other areas. Inspection and processing verification of the fuselage confirm that the size and shape meet the requirements. The water cavity and oil channel have also been pressure tested and meet the requirements. Therefore, it is feasible to adopt the casting system design method for this diesel engine fuselage. The use of the present invention can save 500,000 yuan in material costs and 800,000 yuan in quality costs annually.

[0123] Table 1: Melting ingredient control

[0124]

[0125] Table 2: Melting chemical composition

[0126]

[0127] Table 3: Casting parameter control

[0128]

[0129] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

[0130] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

Claims

1. A large diesel engine body pouring system with a slag removal structure, the pouring system being a bottom pouring open pouring system, comprising a pouring cup (1) placed on the upper portion of a mold, the water outlet of the pouring cup (1) being connected to the inner cavity of the mold through a sprue (2), a runner (3), and an inner runner (4) in sequence, and characterized in that: The pouring cup (1) is a quantitative pouring cup, comprising a pouring cup body (1-1), a vibration device (1-2), a plug removal device (1-3) and a slag retaining ring (1-4); A basic heat-insulating layer is laid on the inner bottom surface of the pouring cup body (1-1); insulating water ports (1-1-5) are provided at both ends of the inner bottom of the pouring cup body (1-1); a molten iron collecting tank (1-1-7) is provided on the outer bottom surface of the insulating water port (1-1-5); the upper end of the insulating water port (1-1-5) is higher than the molten iron collecting tank (1-1-7) to form a slag retaining platform (1-1-8); A slag retaining ring (1-4) is provided around the insulating water outlet (1-1-5); a plugging device (1-3) is fixed on the side wall of the pouring cup body (1-1), and the plug head of the plugging device (1-3) is tightly fitted with the water outlet of the insulating water outlet (1-1-5); the vibration device (1-2) is fixed to the middle part of the outer side of the bottom of the pouring cup body (1-1); The runner (3) is a slag shielding and collecting runner structure with a height-to-width ratio greater than 1. The runner (3) is connected to the ingrown (4) via a molten iron filtering device (7). The ingrown (4) is a structure that gradually changes from a cylindrical shape to an open flat shape. A molten iron closed flow limiting structure is provided between the parting surfaces of the casting mold. The molten iron closed flow limiting structure comprises a closed annular groove (5-1) provided on the parting surface of the lower casting mold (5) of the casting mold within a range of 30-50 mm from the casting, wherein a sealing strip (8) with a diameter of φ3-φ10 mm is provided in the closed annular groove (5-1) and is sandwiched between the upper casting mold (6) and the lower casting mold (5), and a parting gap of no more than 3 mm after the upper casting mold (6) and the lower casting mold (5) are closed.

2. The large diesel engine fuselage pouring system with a slag removal structure according to claim 1, characterized in that: After the pouring cup body (1-1) is welded and formed, a heat-resistant layer A (1-1-1) with a thickness of 3 mm to 5 mm is first laid on the bottom surface of the interior thereof, followed by a 60 mm thick formed refractory material B layer (1-1-2), followed by a 10 mm to 20 mm thick refractory material C layer (1-1-3), and finally a 30 mm thick refractory material D layer (1-1-4) to form a basic heat insulation layer. When laying the basic heat insulation layer, a nozzle position is reserved at each end. A shaped nozzle refractory brick E (1-1-6) is installed at the center of the reserved nozzle position, the upper plane of the shaped nozzle refractory brick E (1-1-6) is 40 mm higher than the bottom plane of the molten iron collecting tank (1-1-7), and refractory material C is filled around the shaped nozzle refractory brick E to make it flush with the shaped nozzle refractory brick E (1-1-6), thereby forming an insulating water nozzle (1-1-5); the shaped nozzle refractory brick E (1-1-6) and the 40 mm higher refractory material C are filled to form a slag retaining platform (1-1-8); A layer of refractory material C with a thickness of 30 mm to 60 mm is laid on the inner surface of the molten iron collecting tank (1-1-7), with both sides thereof being inclined at an angle of 2° to 3° with the plane of the refractory material D layer (1-1-4), i.e., lower in the middle and higher on both sides; and then a layer of formed refractory material D with a thickness of 30 mm is laid on top.

3. The large diesel engine body casting system with a slag removal structure according to claim 1, characterized in that: The vibration device (1-2) comprises a vibration base (1-2-1) fixed to the middle portion of an outer side of the bottom of the pouring cup body (1-1), and a vibrator (1-2-2) is fixed to the vibration base (1-2-1) via a fastening bolt (1-2-3).

4. The large diesel engine fuselage pouring system with a slag removal structure according to claim 1, characterized in that: The plug extraction device (1-3) comprises a refractory plug extraction head (1-3-1), a shaped refractory tube (1-3-2), a plug extraction rod (1-3-3), a plug extraction pressure rod (1-3-5) and a plug extraction bracket (1-3-6). The refractory plug extraction head (1-3-1) and the shaped refractory tube (1-3-2) are sequentially mounted on the plug extraction rod (1-3-3), and the upper and lower parts are locked with nuts (1-3-4); the middle part of the plug extraction pressure rod (1-3-5) is connected to the top end of the plug extraction bracket (1-3-6) by bolt I (1-3-8), and the top end of the plug extraction rod (1-3-3) and the end end of the plug extraction pressure rod (1-3-5) are connected by bolt II (1-3-7).

5. The large diesel engine body casting system with a slag removal structure according to claim 1, characterized in that: The slag retaining ring (1-4) comprises a circular ring L (1-4-1) made of φ8mm round steel welded and adapted to the outer periphery of the insulating water outlet (1-1-5); a layer of refractory material M1 (1-4-2) with a thickness of 3mm is wound around the circular ring L (1-4-1), and then a circle of φ1mm fastening material N1 layer (1-4-3) is wound in the opposite direction; then a layer of 2mm refractory material M2 (1-4-4) is wound on the fastening material N1 layer (1-4-3), and then a circle of φ1mm fastening material N2 layer (1-4-5) is wound in the opposite direction; the above steps are repeated to make the circular ring L (1-4-1) thicker by another 5mm.

6. The large diesel engine body casting system with a slag removal structure according to claim 1, characterized in that: The slag shielding and collecting runner structure on the runner (3) comprises a plurality of slag shielding grooves (3-1) evenly distributed on the inner wall of the runner (3), and a slag collecting bag (3-2) provided at the end of the runner (3).

7. The large diesel engine body casting system with a slag removal structure according to claim 1, characterized in that: The molten iron filtering device (7) comprises a molten iron filter (7-1), a pre-filtration molten iron buffer zone (7-2) is provided on the upper portion of the molten iron filter (7-1), and a post-filtration molten iron buffer zone (7-3) is provided on the lower portion of the molten iron filter (7-1).

8. The large diesel engine body casting system with a slag removal structure according to claim 1, characterized in that: The ingrown channel (4) comprises a cylindrical ingrown channel straight pipe (4-1), the ingrown channel straight pipes (4-1) are connected to each other via a cylindrical ingrown channel bend pipe (4-2), the ingrown channel (4) outlet is connected to the inner cavity of the casting mold via a special-shaped variable-section ingrown channel (4-3), the cross-sectional dimensions of one end of the special-shaped variable-section ingrown channel (4-3) are the same as those of the ingrown channel straight pipe (4-1) and the ingrown channel bend pipe (4-2), and the cross-sectional dimensions of the other end of the special-shaped variable-section ingrown channel (4-3) are gradually enlarged to 1.5 to 3 times, and the end thereof is a rectangle with an aspect ratio of 3 to 8.

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