Double-shaft slag ladle and molding method of casting mould of double-shaft slag ladle

Abstract

The invention discloses a double-shaft slag ladle and a molding method of a casting mould of the double-shaft slag ladle, belongs to the technical field of casting processes, and aims to solve the technical problems of low dimensional precision, poor surface quality and high rejection rate in traditional casting. The method comprises the following core steps that a bottom box plane is manufactured, and self-hardening sand is laid; the positions of the trunnion and the supporting shaft are precisely calibrated through the steel positioning core and the positioning rod; weak areas are welded and reinforced, and layered sand discharging is conducted; alcohol-based paint is brushed in a prepared cavity, and high-pressure air blowing is conducted after polishing; positioning pins are adopted for box closing, so that uniform wall thickness of the cavity is ensured. By optimizing the positioning precision, the sand mold homogenization control and the coating process, the casting quality is remarkably improved, the positioning error of the trunnion and the supporting shaft is reduced, the sand burning rate is decreased, the rejection rate is decreased, and the production period is shortened. The method is suitable for high-precision slag ladle casting in industries such as metallurgy and chemical engineering, the service life of equipment is greatly prolonged, and the operation stability of the equipment is greatly improved.

Description

Technical Field

[0001] The present invention relates to the technical field of casting processes, and particularly to a biaxial slag pot and a molding method for its casting mold. Background Art

[0002] In the field of casting, as a key equipment in the chemical, metallurgical, and energy industries, the slag pot needs to operate stably for a long time in high-temperature, high-pressure, and corrosive environments. Its structural accuracy and surface quality directly affect the equipment life and production safety. The traditional casting methods for biaxial slag pots generally have the following problems: Wooden molds are easily affected by environmental temperature and humidity, and are prone to warping and deformation during storage or use, resulting in dimensional deviation of castings exceeding the tolerance, and further causing uneven stress on the biaxial structure or even cracking of the tank body; The positioning of the trunnion and the support shaft relies on manual scribing or simple tooling, with low positioning accuracy, causing jamming of the tipping mechanism and safety hazards; Uneven sand mold compaction leads to surface sand sticking, sand washing, and internal porosity defects, and improper control of the reaction time of self-hardening sand or too thick sand layer is prone to cause delamination; The traditional coating application process is rough, with random Baume degrees and only 3 - 5 coating passes, resulting in insufficient coating thickness or poor fluidity, increased sand sticking rate, and extended cleaning man-hours; In addition, the high scrap rate and long production cycle significantly increase the cost. Existing improvement attempts such as steel molds or numerical control positioning tooling have partially improved the accuracy, but are still affected by the thermal deformation of the sand mold, and the resin sand process has not completely solved the delamination problem due to the lack of standardized parameters. Therefore, there is an urgent need for a casting method that takes into account high precision, sand mold homogenization, coating optimization, and high-efficiency production to fill the technical gap in the industry. Summary of the Invention

[0003] The present invention provides a biaxial slag pot and a molding method for its casting mold. By designing the mold manufacturing process, optimizing the operation process, and adopting reliable and stable process implementation means, the high-efficiency, precision, and high-quality casting of the biaxial slag pot are achieved. The specific content of the invention is as follows: A biaxial slag pot includes a tank body. A tank mouth flange is provided at the opening of the tank body. Trunnion bases are provided on both sides of the tank body. Trunnions are provided inside the trunnion bases. Support shaft bases are provided on both sides of the tank body, and the support shaft bases are arranged below the trunnion bases. Support shafts are provided inside the support shaft bases. Reinforcing transverse ribs are provided on the side of the tank body, and reinforcing vertical ribs are provided on the reinforcing transverse ribs. A tipping mechanism is provided at the bottom of the tank body, and the tipping mechanism includes a tipping arm and a base.

[0004] Further, a trunnion is provided on the side of the trunnion base away from the tank body. The side of the trunnion base away from the tank body is perpendicular to the ground, and the side of the trunnion base away from the tank body is flush with the side edge of the tank mouth flange.

[0005] Further, the tank body includes four side plates and a tank bottom. The four side plates are symmetrically arranged in pairs with the central axis of the tank body as the center. The tank bottom is an arc surface, and the upper end of the tank bottom is connected to the lower end of the side plates. The longitudinal section of the tank body is U-shaped.

[0006] Furthermore, the support shaft has a double-axis structure and is arranged horizontally. The support shaft includes two shaft bodies, which are symmetrically arranged along the central axis of the tank body. A connecting plate I is provided between the two shaft bodies and is arranged horizontally. A connecting plate II is provided at the lower ends of the two shaft bodies and is arranged horizontally.

[0007] Furthermore, the tipping arm is perpendicular to the line connecting the left and right trunnions.

[0008] Furthermore, it includes the following steps: S1. Making the bottom box plane: Select the bottom box, the area of which is larger than the area of the tank mouth flange. Place the bottom box in the molding pit, adjust the upper edge of the bottom box to be horizontal, lay evenly mixed self-hardening sand in the bottom box and scrape the sand surface flat, and wait for it to harden naturally; S2. Fixing and positioning: On the hardened sand surface of the bottom box, sequentially place and install the casting pattern and the positioning device. The casting pattern includes the tank body pattern, the trunnion base pattern, the support shaft base pattern, the strengthening transverse rib pattern, the strengthening vertical rib pattern and the tipping mechanism pattern. The positioning device includes trunnions, trunnion positioning cores, support shaft sleeves and positioning rods. The tank body pattern is placed with the opening downward on the sand surface of the bottom box. The trunnion base pattern, the support shaft base pattern, the strengthening transverse rib pattern, the strengthening vertical rib pattern and the tipping mechanism pattern are sequentially installed on the tank body pattern. Then, install the trunnion positioning core in the trunnion base pattern, install the support shaft sleeve in the support shaft base pattern, and weld the positioning rod between the trunnion and the support shaft sleeve; S3. Welding and reinforcement: Use round steel to weld and fix the trunnions, support shafts and the sand box. There is a weak area of the sand mold eating sand amount at the side plate of the tank body. Weld steel core bones with a diameter of φ14 - φ30 in the weak area of the sand mold eating sand amount, and the core bones are welded to the sand box; S4. Sand placement and molding: Mix self-hardening sand according to the mass ratio of resin, curing agent and sand of 100:1.2 - 1.3:0.5 - 0.6, and control the sand layer thickness to be between 300 - 400 mm; S5. Pattern removal and mold repair: After the sand mold is cured for 20 hours, remove the pattern, including the support shaft sleeve, the wooden support shaft base pattern, the foam trunnion base pattern, the strengthening transverse rib pattern, the strengthening vertical rib pattern and the tipping mechanism pattern, and then polish and trim the surface of the cavity formed after the sand mold is cured; S6. Coating application: Uniformly apply multiple coats of alcohol-based coating to the surface of the cavity. The interval time between each coat application is 15 - 20 minutes, and the total coating thickness is 1.5 - 2 mm. After the last coat application, use sandpaper to polish and blow the surface with high-pressure air; S7. Casing and pouring: Align the upper box and the lower box through the integral positioning pins of the sand mold, check the uniformity of the cavity wall thickness, and ensure that there is no misalignment at the casing joint.

[0009] Furthermore, in step S2, the trunnion base pattern, the strengthening transverse rib pattern, the strengthening vertical rib pattern and the tipping mechanism pattern are foam patterns, and the support shaft base pattern is a wooden pattern.

[0010] Further, the Baume degree of the alcohol-based coating described in step S6 is 40-60, and it is evenly applied 5-10 times.

[0011] Further, the Baume degree of the alcohol-based coating described in step S6 is 50±2, it is evenly applied 8 times, and polished with 50-80 mesh sandpaper.

[0012] Further, it is characterized in that a φ30 round steel is used for welding connection between the trunnion and the support shaft, and the welding length is not less than 1.5 times the diameter of the trunnion.

[0013] The technical solution adopted by the present invention can achieve the following beneficial effects: 1. The dimensional accuracy is significantly improved: The positioning accuracy of the trunnion and the support shaft: The steel positioning core and the electronic level are used for calibration, the tolerance of the center distance of the trunnion is reduced, the levelness deviation is reduced, and the problem of the tank body cracking caused by uneven stress of the double-shaft structure is completely solved.

[0014] The wall thickness uniformity of the cavity: Through the sand mold integral positioning pin and the control of the mold closing gap, the wall thickness tolerance of the cavity is narrowed, ensuring the structural stability of the slag pot.

[0015] 2. The surface quality is comprehensively improved: Coating process optimization: An alcohol-based coating with a Baume degree of 50±1 is used, applied 8 times, combined with high-pressure air sweeping and sandpaper polishing, the sand sticking rate of the casting is reduced compared with the traditional process, and the cleaning man-hours are shortened.

[0016] Sand mold defect control: The layered sand placing process and the core frame strengthening reduce the difference in the compactness of the sand mold from [original value] to [new value], significantly reducing defects such as air holes and sand washing.

[0017] 3. The production efficiency is greatly improved: The production cycle is shortened: Through the standardized process and mechanized operation, the single-piece slag pot production cycle is shortened from the traditional 120 hours to 72 hours, and the efficiency is increased by 40%.

[0018] The scrap rate is reduced: The sand mold layering rate is reduced from 8%-10% to <2%, the welding strength ≥300MPa, and the comprehensive scrap rate is reduced from 15%-20% to below 1.5%, directly reducing the rework cost by more than 25%.

[0019] 4. The economy and applicability are enhanced Material cost optimization: The combined design of wooden mold and steel mold is adopted, the steel positioning device is used in the key parts, and the wooden mold and foam mold are retained in the non-key areas. The mold cost is only 20%-30% of the all-steel mold, and at the same time, the problem of wooden mold deformation is avoided.

[0020] Process compatibility: The method is applicable to slag pots of different specifications. By adjusting the dimensions of the positioning core and the sand layer parameters, it can quickly adapt to diverse production requirements. Brief Description of the Drawings

[0021] Figure 1 This is the front view of the present invention; Figure 2 This is the bottom view of the present invention; Figure 3 This is the right view of the present invention; Figure 4 This is the side sectional view of the present invention; In the figure, 1 - tank body, 2 - side plate, 3 - tank bottom, 4 - tank mouth flange, 5 - trunnion base, 6 - trunnion, 7 - support shaft base, 8 - support shaft, 801 - connecting plate Ⅰ, 802 - connecting plate Ⅱ, 803 - shaft body, 804 - support shaft bushing, 9 - reinforcing transverse rib, 10 - reinforcing vertical rib, 11 - tipping arm, 12 - base, 13 - positioning rod. Detailed Embodiment

[0022] The technical solution of the present invention will be further described below with reference to the drawings.

[0023] As Figures 1-4 shown, a double - shaft slag pot, characterized in that it includes a tank body 1, the tank body 1 includes four side plates 2 and a tank bottom 3, the four side plates 2 are symmetrically arranged in pairs with the central axis of the tank body 1 as the center, the tank bottom 3 is an arc surface, the upper end of the tank bottom 3 is connected to the lower end of the side plate 2, the longitudinal section of the tank body 1 is U - shaped, a tank mouth flange 4 is provided at the opening of the tank body 1, trunnion bases 5 are provided on both sides of the tank body 1, a trunnion 6 is provided inside the trunnion base 5, the trunnion 6 is arranged on the side of the trunnion base 5 away from the tank body 1, the side surface of the trunnion base 5 away from the tank body 1 is perpendicular to the ground, the side surface of the trunnion base 5 away from the tank body 1 is flush with the side edge of the tank mouth flange 4, support shaft bases 7 are provided on both sides of the tank body 1, the support shaft bases 7 are arranged below the trunnion bases 5, a support shaft 8 is provided inside the support shaft base 7, the support shaft 8 is a double - shaft structure, the support shaft 8 is arranged in the horizontal direction, the support shaft 8 includes two shaft bodies 803, the two shaft bodies 803 are symmetrically arranged with the central axis of the tank body 1 as the center, a connecting plate Ⅰ801 is provided between the two shaft bodies 803, the connecting plate Ⅰ801 is arranged in the horizontal direction, connecting plates Ⅱ802 are provided at the lower ends of the two shaft bodies 803, the connecting plates Ⅱ802 are arranged in the horizontal direction, a reinforcing transverse rib 9 is provided on the side part of the tank body 1, a reinforcing vertical rib 10 is provided on the reinforcing transverse rib 9, a tipping mechanism is provided at the bottom of the tank body 1, the tipping mechanism includes a tipping arm 11 and a base 12, and the tipping arm 11 is perpendicular to the connection line between the left and right trunnions 6.

[0024] A mold - making method for a double - shaft slag pot includes the following steps: S1. Fabricate the bottom box plane: Select the bottom box, whose area is larger than the area of the ladle flange 4. Place the bottom box in the molding pit and adjust it through shims to a flatness error ≤ 0.5 mm / m². Lay evenly mixed self-hardening sand in the bottom box and scrape the sand surface flat. Wait for it to harden naturally, controlling the laying speed and thickness to ensure uniformity and no delamination. After hardening, clean the surface impurities. S2. Fixing and positioning: On the hardened sand surface of the bottom box, sequentially place and install the casting pattern and the positioning device. The casting pattern includes the pattern of the tank body 1, the pattern of the trunnion base 5, the pattern of the support shaft base 7, the pattern of the strengthening transverse rib 9, the pattern of the strengthening vertical rib 10, and the pattern of the tipping mechanism. The positioning device includes the trunnion 6, the trunnion positioning core, the support shaft bushing 804, and the positioning rod 13. Among them, the patterns of the trunnion base 5, the strengthening transverse rib 9, the strengthening vertical rib 10, and the tipping mechanism are made of foam, and the pattern of the support shaft base 7 is made of wood. The pattern of the tank body 1 is placed with the opening downward on the sand surface of the bottom box. The patterns of the trunnion base 5, the support shaft base 7, the strengthening transverse rib 9, the strengthening vertical rib 10, and the tipping mechanism are sequentially installed on the pattern of the tank body 1. Then install the trunnion positioning core in the trunnion base 5. Install the trunnion positioning core on the side of the trunnion base 5 away from the pattern of the tank body 1, align the central vertical line of the trunnion positioning core with the central vertical line of the slag ladle pattern, and then install the trunnion 6 on the trunnion positioning core. After the positioning of the trunnion 6 is completed, pass the lower end of the positioning rod 13 through the pattern of the trunnion base 5 and weld it above the trunnion 6 to ensure that the positioning rod 13 is perpendicularly welded. Then install the pattern of the support shaft base 7 on the pattern of the tank body 1. The pattern of the support shaft base 7 is located above the trunnion base 5. The pattern of the support shaft base 7 also includes a vertical rib pattern, which is arranged along the center line of the side of the pattern of the tank body 1. The vertical rib pattern is arranged on the upper side of the pattern of the support shaft base 7 and fits against the pattern of the tank body 1. The support shaft bushing 804 is horizontally inserted into the pattern of the support shaft base 7 and is used to jointly form the support shaft 8 with the molten steel cooled in the support shaft bushing 804 after casting. The support shaft bushing 804 includes the connecting plate Ⅰ 801 and the connecting plate Ⅱ 802. The center line of the connecting plate Ⅰ 801, the center line of the connecting plate Ⅱ 802, and the center line of the pattern of the tank body 1 are in the same plane. Weld the positioning rod 13 between the trunnion 6 and the support shaft bushing 804. The positioning rod 13 is welded on the center line of the connecting plate Ⅱ 802. The lower side of the pattern of the support shaft base 7 is welded to the upper end of the positioning rod 13 to ensure that the support shaft 8 remains horizontal.The outer wall of the slag pot mold is provided with a reinforcing transverse rib 9 pattern, which is arranged in the middle of the slag pot mold and surrounds the outer wall of the slag pot mold. Four reinforcing vertical ribs 10 patterns are evenly distributed on both sides of the reinforcing transverse rib 9 pattern where there is no ear shaft 6. A tilting mechanism pattern is provided on the outer wall of the slag pot mold away from the opening of the tank body 1. The tilting arm 11 of the tilting mechanism pattern is perpendicular to the connecting line of the ear shafts 6 on both sides; S3. Welding reinforcement: The ear shaft 6, the support shaft 8 and the sand box are welded and fixed by round steel. The ear shaft 6 and the support shaft 8 are welded and connected by φ30 round steel. The welding length is not less than 1.5 times the diameter of the ear shaft 6. There is a weak area of sand mold sand intake at the side plate 2 of the tank body 1. A φ30 steel core bone is welded in the weak area of sand mold sand intake. The core bone is welded to the sand box. The welding core bone can strengthen the sand mold to improve its bearing capacity, and can also avoid sand loss and reduce casting quality problems; S4. Sand forming: Mix self-hardening sand according to the mass ratio of resin, curing agent and sand of 100:1.3:0.6, control the thickness of the sand layer to be between 380mm, and use a tamping machine to tamp the area close to the pattern immediately after sand is placed; S5. Mold removal and mold repair: Mold the sand mold after 20 hours of curing. When removing the mold, the sand mold should be hung as flat as possible to avoid damaging the sand mold or the pattern. Remove the casting pattern attached to the sand mold, including the wooden support shaft base 7 pattern, the foam ear shaft base 5 pattern, the reinforced horizontal rib 9 pattern, the reinforced vertical rib 10 pattern and the tilting mechanism pattern. After demolding, grind and trim the surface of the cavity to ensure that the surface flatness error is ≤0.5mm, and perform fillet grinding on the sharp corners and the vicinity of the reinforcing ribs of the sand mold, remove excess sand and foam accessories, and make the surface of the sand mold flat and smooth; S6. Paint painting: Apply multiple coats of alcohol-based paint with a Baume degree of 50±2 evenly to the surface of the cavity, and apply evenly 8 times, with an interval of 20 minutes between each coat. At the same time, pay attention to avoid stratification caused by excessive thickness of the paint. The total coating thickness is 2mm. After the last coat, use 80-grit sandpaper to polish and blow the surface with high-pressure wind; S7. Combination and pouring: Use the integrated positioning pins of the sand mold to align the upper box with the lower box. The integrated positioning pins of the sand mold are cylindrical pins prefabricated manually during molding, with a diameter tolerance of ±0.2mm. Check the uniformity of the cavity wall thickness to ensure that there is no misalignment in the box-joining seam and the gap is ≤0.3mm. Pre-place the steel support shaft sleeve 804 in the cavity position of the support shaft 8, and then accurately align the upper box with the lower box through the positioning pins on the sand mold and tighten them. Pay attention to controlling the strength and speed of the box-joining to avoid damage or misalignment of the sand mold. After the box is assembled, check whether the assembly is good, ensure that the wall thickness of the slag pot cavity is uniform, and there is no gap or misalignment in the assembly seam. If there is any problem, make adjustments in time.

Claims

1. A double-shaft slag ladle, characterized in that, It includes a tank body (1). A tank mouth flange (4) is provided at the opening of the tank body (1). Trunnion bases (5) are provided on both sides of the tank body (1). Trunnions (6) are arranged inside the trunnion bases (5). Support shaft bases (7) are provided on both sides of the tank body (1). The support shaft bases (7) are arranged below the trunnion bases (5). Support shafts (8) are arranged inside the support shaft bases (7). Reinforcing transverse ribs (9) are provided on the side of the tank body (1). Reinforcing vertical ribs (10) are provided on the reinforcing transverse ribs (9). A tipping mechanism is provided at the bottom of the tank body (1). The tipping mechanism includes a tipping arm (11) and a base (12).

2. The double-shaft slag ladle according to claim 1, characterized in that, A trunnion (6) is provided on the side of the trunnion base (5) away from the tank body (1). The side of the trunnion base (5) away from the tank body (1) is perpendicular to the ground, and the side of the trunnion base (5) away from the tank body (1) is flush with the side edge of the tank mouth flange (4).

3. A double-shaft slag ladle according to claim 2, characterized in that, The tank body (1) includes four side plates (2) and a tank bottom (3). The four side plates (2) are symmetrically arranged in pairs with the central axis of the tank body (1) as the center. The tank bottom (3) is an arc surface. The upper end of the tank bottom (3) is connected to the lower end of the side plate (2). The longitudinal section of the tank body (1) is U-shaped.

4. A double-shaft slag ladle according to claim 3, characterized in that, The support shaft (8) has a double-shaft structure. The support shaft (8) is arranged horizontally. The support shaft (8) includes two shaft bodies (803). The two shaft bodies (803) are symmetrically arranged with the central axis of the tank body (1) as the center. A connecting plate I (801) is provided between the two shaft bodies (803). The connecting plate I (801) is arranged horizontally. Connecting plates II (802) are provided at the lower ends of the two shaft bodies (803). The connecting plates II (802) are arranged horizontally.

5. A double-shaft slag ladle according to claim 3, characterized in that, The tipping arm (11) is perpendicular to the line connecting the left and right trunnions (6).

6. A molding method for a biaxial slag ladle mold according to claims 1-5, characterized in that, It includes the following steps: S1. Making the bottom box plane: Select a bottom box. The area of the bottom box is larger than the area of the tank mouth flange (4). Place the bottom box in the molding pit, adjust the upper edge of the bottom box to be horizontal, lay uniformly mixed self-hardening sand in the bottom box and scrape the sand surface flat, and wait for it to harden naturally; S2. Fixing and positioning: On the hardened sand surface of the bottom box, place and install the casting pattern and the positioning device in sequence. The casting pattern includes the pattern of the tank body (1), the pattern of the trunnion base (5), the pattern of the support shaft base (7), the pattern of the reinforcing transverse rib (9), the pattern of the reinforcing vertical rib (10), and the pattern of the tipping mechanism. The positioning device includes the trunnion (6), the trunnion positioning core, the support shaft bushing (804), and the positioning rod (13). The pattern of the tank body (1) is placed with the opening facing down on the sand surface of the bottom box. The patterns of the trunnion base (5), the support shaft base (7), the reinforcing transverse rib (9), the reinforcing vertical rib (10), and the tipping mechanism are installed on the pattern of the tank body (1) in sequence. Then, install the trunnion positioning core in the pattern of the trunnion base (5), install the support shaft bushing (804) in the pattern of the support shaft base (7), and weld the positioning rod (13) between the trunnion (6) and the support shaft bushing (804); S3. Welding reinforcement: Use round steel to weld and fix the trunnion (6) and the support shaft (8) to the sand box. There is a weak area of the sand mold eating sand amount at the side plate (2) of the tank body (1). Weld a steel core bone with a diameter of φ14 - φ30 in the weak area of the sand mold eating sand amount, and the core bone is welded to the sand box; S4. Sand placement and molding: Mix self-hardening sand according to the mass ratio of resin, curing agent, and sand of 100:1.2 - 1.3:0.5 - 0.6, and control the sand layer thickness to be between 300 - 400 mm; S5. Pattern removal and mold repair: After the sand mold is cured for 20 hours, remove the pattern. Remove the patterns that fit on the sand mold, including the pattern of the wooden support shaft base (7), the pattern of the foam trunnion base (5), the pattern of the reinforcing transverse rib (9), the pattern of the reinforcing vertical rib (10), and the pattern of the tipping mechanism. Then, grind and trim the surface of the cavity formed after the sand mold is cured; S6. Coating application: Uniformly apply multiple coats of alcohol-based coating to the cavity surface. The interval time between each coat application is 15 - 20 minutes, and the total coating thickness is 1.5 - 2 mm. After the last coat is applied, use sandpaper to polish and blow the surface with high-pressure air; S7. Flask closing and pouring: Align the upper flask and the lower flask through the integral positioning pins of the sand mold, check the uniformity of the cavity wall thickness, and ensure that there is no misalignment at the flask closing joint.

7. A molding method for a biaxial slag ladle mold according to claim 6, characterized in that, In step S2, the patterns of the trunnion base (5), the reinforcing transverse rib (9), the reinforcing vertical rib (10), and the tipping mechanism are foam patterns, and the pattern of the support shaft base (7) is a wooden pattern.

8. A molding method for a biaxial slag ladle mold according to claim 7, characterized in that, In step S6, the Baume degree of the alcohol-based coating is 40 - 60, and it is uniformly applied 5 - 10 times.

9. A molding method for a biaxial slag ladle mold according to claim 8, characterized in that, In step S6, the Baume degree of the alcohol-based coating is 50 ± 2, and it is uniformly applied 8 times, and polished with 50 - 80 mesh sandpaper.

10. A molding method for a biaxial slag ladle mold according to claim 9, characterized in that, The trunnion (6) and the support shaft (8) are welded and connected with φ30 round steel, and the welding length is not less than 1.5 times the diameter of the trunnion (6).

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