A heat treatment furnace and method for nodular cast iron well covers

Abstract

The application discloses a nodular cast iron well lid post-casting heat treatment furnace and a heat treatment method, relates to the technical field of well lid heat treatment, and comprises a heat treatment furnace main body, a chute is arranged in the heat treatment furnace main body, a sliding plate matched with the chute is slidingly installed in the chute, a material placing plate is fixedly connected to the top end of the sliding plate, two transverse grooves are formed in the right side wall of the heat treatment furnace main body, balance bars are slidingly installed in the two transverse grooves, a mounting seat is fixedly connected to the right ends of the two balance bars, and a supporting shaft is rotatably installed on the top of the mounting seat. The heat treatment furnace main body is provided with a sliding cantilever support structure on the outside, and the sliding cantilever support structure is supported by rotating a support plate, so that stable support and automatic accurate positioning of the material placing plate during loading are realized.

Description

Technical Field

[0001] This application relates to the field of heat treatment technology for manhole covers, and in particular to a heat treatment furnace and heat treatment method for ductile iron manhole covers after casting. Background Technology

[0002] Ductile iron manhole covers are load-bearing components widely used in municipal and transportation fields. Their mechanical properties directly affect their safety and lifespan. Eliminating casting stress and optimizing the matrix structure are crucial to achieving high strength, high toughness, and good wear resistance. Post-casting heat treatment is a key process in the production of ductile iron manhole covers. Heat treatment furnaces are commonly used to perform heat treatments such as annealing and normalizing on the manhole covers.

[0003] In existing production practices, to improve operational efficiency, multiple manhole covers are typically pre-stacked neatly on a dedicated high-temperature resistant steel rack (or material rack, material tray), and then transported into the heat treatment furnace by forklifts or other handling equipment. However, in actual applications, due to the limited size of the furnace door and the limited operating space inside the furnace, and the large volume and low flexibility of the rack along with the manhole covers it carries, forklift drivers, limited by visual constraints and operational precision, are prone to scratching or even colliding with the inner wall of the furnace door, the side wall of the furnace, or critical components such as internal heating elements when positioning the rack into the furnace, damaging the rack and the precision components inside the furnace. Summary of the Invention

[0004] The purpose of this application is to solve the problems in the background art by proposing a heat treatment furnace and heat treatment method for ductile iron manhole covers after casting.

[0005] To achieve the above objectives, this application adopts the following technical solution: A heat treatment furnace for ductile iron manhole covers after casting includes a furnace body. A sliding groove is provided inside the furnace body, and a matching sliding plate is slidably installed within the groove. A material placement plate is fixedly connected to the top of the sliding plate. Two transverse grooves are formed on the right side wall of the furnace body, and balance bars are slidably installed in each groove. A mounting base is fixedly connected to the right end of both balance bars. A support shaft is rotatably installed on the top of the mounting base, and a rotating support plate is fixedly attached to the top of the support shaft. A positioning frame is fixedly connected to the bottom of the sliding plate. A vertical plate is fixedly connected to the top of the mounting base. A laterally movable insert rod is provided on the left side of the vertical plate. A rotating rod is rotatably installed on the top of the mounting base via a bearing. A gear plate and a turning plate are fixedly connected to the outer wall of the rotating rod. A gear plate meshing with the gear plate is fixedly connected to the right outer wall of the furnace body. A horizontal plate is fixedly connected to the left end of the insert rod, and the horizontal plate is positioned on the rotation path of the turning plate.

[0006] In the above-mentioned heat treatment furnace for ductile iron manhole covers, a protrusion is fixedly connected to the top of the mounting base, a rotating shaft is rotatably mounted on the top of the protrusion, and a baffle is fixedly connected to the outer wall of the rotating shaft. Both the baffle and the upright plate are provided with transverse through holes, and a connecting rod is movably inserted into the through hole of the baffle.

[0007] In the above-mentioned heat treatment furnace for ductile iron manhole covers, a crossbar is fixedly connected to the outer right side of the furnace body. When the connecting rod passes through the through holes of the baffle and the vertical plate simultaneously, the connecting rod and the crossbar are in a coaxial state.

[0008] In the above-mentioned heat treatment furnace for ductile iron manhole covers after casting, a placement slot is provided on the right side of the mounting base, and the top of the placement slot is in an open state.

[0009] In the above-mentioned heat treatment furnace for ductile iron manhole covers after casting, a connecting rope is connected between the left side of the horizontal plate and the left side of the vertical plate.

[0010] In the above-mentioned heat treatment furnace for ductile iron manhole covers after casting, a connecting piece is fixedly connected to the right end of the connecting rod, and a connecting rope is connected between the connecting piece and the baffle.

[0011] In the above-mentioned heat treatment furnace for ductile iron manhole covers, translation grooves are respectively opened on the front and rear sides of the material placement plate, and a slider is slidably installed in each translation groove. A limit frame is fixedly connected between two sliders.

[0012] A heat treatment method for ductile iron manhole covers after casting, achieved in a heat treatment furnace, includes the following steps: S1: Extend the material plate out of the heat treatment furnace body, rotate the rotating support plate upward and place it in the positioning frame, then connect the connecting rod through the baffle and connect it to the upright plate to provide a locking effect for the rotating support plate, and insert the insertion rod through the upright plate and insert it into the rotating support plate.

[0013] S2: Push or hoist the shelf with the manhole cover onto the supported material plate, and ensure that the shelf is centered on the material plate. Push the limiting frame to slide along the translation groove so that its inner wall and the outer contour of the shelf maintain a uniform gap.

[0014] S3: The forklift slowly pushes the slide plate along the chute into the heat treatment furnace. During the movement, the mounting base moves to the left. Because the toothed disc meshes with the toothed plate fixed on the furnace body, it drives the rotating rod to rotate counterclockwise. The actuating plate on the rotating rod rotates accordingly, pushing the horizontal plate and the insert rod to the left, causing the insert rod to exit from the hole in the vertical plate and the rotating support plate. The rotating support plate automatically unlocks. As the slide plate continues to push inward, the left end of the connecting rod contacts the horizontal bar fixed on the furnace body. Under the obstruction of the horizontal bar, the connecting rod is pushed to the right and disengaged from the vertical plate. At this time, the rotating support plate is completely unlocked and rotates to the right around the support axis under its own weight, gradually disengaging from below the positioning frame and returning to the non-interference position.

[0015] S4: Continue pushing the slide plate until the material placement plate and its shelf are fully inside the predetermined position of the heat treatment furnace body. Close the furnace door and heat treat the manhole cover according to the set heat treatment process curve. After the heat treatment process is completed, open the furnace door and use a forklift to pull the slide plate outward to move the material placement plate and the heat-treated manhole cover out of the furnace. When the slide plate moves outward to a longer extension section, the rotating support plate can be manually or assisted to rotate upward to the support position and insert the insertion rod for temporary fixation in preparation for the next loading.

[0016] Compared with existing technologies, the advantages of this application are as follows: By setting a sliding cantilever support structure on the outside of the heat treatment furnace body and supporting it with a rotating support plate, stable support and automatic precise positioning of the material plate are achieved during the loading process. During the loading stage, the rotating support plate can provide rigid support for the cantilever section of the slide plate, effectively preventing it from bending and deforming due to load. During the feeding process, the locking of the insertion rod is automatically released through the meshing transmission of the toothed disc and toothed plate, and a secondary automatic unlocking is achieved through the cooperation of the crossbar and the docking rod, so that the support structure is completely detached in the later stage of feeding. No manual intervention is required throughout the process, which completely avoids the problem of scraping and collision between the rack and the furnace wall caused by insufficient forklift operation precision, improves the feeding positioning accuracy and operational safety, protects the precision components inside the furnace, and reduces the labor intensity of operators and production safety hazards. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a post-casting heat treatment furnace for ductile iron manhole covers proposed in this application; Figure 2 This is a schematic diagram of the chute installation in this application; Figure 3 This is a schematic diagram of the installation of the rotating support plate in this application; Figure 4 This is a schematic diagram of the installation of the limit frame in this application; Figure 5 This is a schematic diagram of the mounting base structure for this application; Figure 6 This is a schematic diagram of the baffle installation in this application; Figure 7 This is a schematic diagram of the insertion rod installation in this application.

[0018] In the diagram: 1. Main body of the heat treatment furnace; 2. Slide groove; 3. Slide plate; 4. Material feeding plate; 5. Limiting frame; 6. Positioning frame; 7. Balance bar; 8. Mounting base; 9. Rotating rod; 10. Gear plate; 11. Gear plate; 12. Actuating plate; 13. Vertical plate; 14. Insert rod; 15. Horizontal plate; 16. Rotating support plate; 17. Protrusion; 18. Rotating shaft; 19. Baffle; 20. Connecting rod; 21. Crossbar. Detailed Implementation

[0019] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] Reference Figures 1-7 A heat treatment furnace and heat treatment method for ductile iron manhole covers after casting are disclosed. The furnace body 1 includes a main body 1, a chute 2 inside the furnace body 1, and a matching slide plate 3 slidably installed in the chute 2. The slide plate 3 is composed of two inverted T-shaped plates welded together to prevent it from detaching from the chute 2. A material placement plate 4 is welded and fixed to the top of the slide plate 3. Translation grooves are opened on the front and rear sides of the material placement plate 4, and a slider is slidably installed in each translation groove. A limit frame 5 is welded between the two sliders. The outer diameter of the limit frame 5 is the same as the inner diameter of the furnace body 1. During operation, the rack carrying the manhole cover is placed on the material placement plate 4. The position of the limit frame 5 is adjusted by the translation grooves and sliders to prevent it from colliding with the rack during movement. Then, a forklift pushes the slide plate 3 along the chute 2 into the furnace body 1 to install the manhole cover.

[0021] Two transverse grooves are provided on the right side of the heat treatment furnace body 1. Each groove is equipped with a balance bar 7. The right ends of the two balance bars 7 are welded together with a mounting base 8. A U-shaped block is welded to the top of the mounting base 8. A support shaft is rotatably mounted inside the U-shaped block via a bearing. A rotating support plate 16 is welded to the top of the support shaft. A positioning frame 6 matching the width of the rotating support plate 16 is welded to the bottom of the slide plate 3. The rotating support plate 16 can rotate upward around the support shaft to fit against the top wall of the positioning frame 6, thereby providing support for the cantilevered section of the slide plate 3 extending outside the heat treatment furnace body 1, and preventing the slide plate 3 from bending and deforming due to excessive cantilever length, thus preventing it from sliding into the slide groove 2.

[0022] A vertical plate 13 is welded to the top of the mounting base 8, located on the left side of the rotating support plate 16. When the rotating support plate 16 rotates upward to a vertical position, its side contacts the vertical plate 13. An insertion rod 14 is provided on the left side of the vertical plate 13. The insertion rod 14 can pass through the vertical plate 13 laterally and be inserted into the corresponding hole of the rotating support plate 16 to limit the rotation of the rotating support plate 16. A horizontal plate 15 is welded to the left end of the insertion rod 14. The horizontal plate 15 is connected to the left side of the vertical plate 13 by multiple connecting ropes to prevent the horizontal plate 15 and the insertion rod 14 from being lost.

[0023] A U-shaped frame is welded to the top of the mounting base 8. A rotating rod 9 is rotatably mounted in the U-shaped frame via a bearing. A toothed disc 10 is welded to the outer wall of the rotating rod 9. A toothed plate 11 that meshes with the toothed disc 10 is welded to the outer wall of the right side of the heat treatment furnace body 1. The top surface of the toothed plate 11 is at the same horizontal height as the bottom surface of the toothed disc 10. A toggle plate 12 is also welded to the outer wall of the rotating rod 9. The rotation trajectory of the toggle plate 12 passes through the position of the horizontal plate 15. When the mounting base 8 moves to the left, the toothed disc 10 meshes with the toothed plate 11, causing the toothed disc 10 to rotate counterclockwise, which drives the toggle plate 12 to rotate synchronously and pushes the horizontal plate 15 to the left. This causes the insertion rod 14 to exit from the vertical plate 13 and the rotating support plate 16, thus automatically releasing the lock on the rotating support plate 16 during the process of pushing the material plate 4 into the furnace, without the need for manual removal of the insertion rod 14.

[0024] The mounting base 8 has a protrusion 17 welded to its top, which is located on the back of the rotating support plate 16. The top of the protrusion 17 is rotatably mounted with a rotating shaft 18 via a bearing. A baffle 19 is welded to the outer wall of the rotating shaft 18. When the rotating support plate 16 is in a vertical state, the left side of the baffle 19 can abut against the right side of the rotating support plate 16, together with the upright plate 13, to restrict the rotating support plate 16 to remain vertical.

[0025] Both the baffle 19 and the upright plate 13 have transverse through holes. A connecting rod 20 is movably inserted into the through hole of the baffle 19. A connecting piece is welded to the right end of the connecting rod 20. The connecting piece is connected to the baffle 19 by a connecting rope to prevent the connecting rod 20 from coming out and being lost.

[0026] A crossbar 21 is welded to the outer right side of the heat treatment furnace body 1. When the connecting rod 20 passes through the through holes of the baffle 19 and the vertical plate 13, the connecting rod 20 is in a horizontal state and is coaxially set with the crossbar 21. During the process of sending the material plate 4 into the heat treatment furnace body 1, the rotating support plate 16 always provides support for the slide plate 3 and the material plate 4. When the material plate 4 is about to be completely entered into the furnace, the left end of the connecting rod 20 contacts the crossbar 21 and is pushed by the crossbar 21 during the continued movement, causing the connecting rod 20 to disengage from the vertical plate 13. At this time, the rotating support plate 16 loses its lock and rotates downward under its own weight, moving away from its working position, thereby avoiding interference from the rotating support plate 16 when the material plate 4 is completely entered into the furnace.

[0027] The mounting base 8 has a placement slot on its right side. The top of the placement slot is open. When the connecting rod 20 loses contact with the upright plate 13, it will rotate with the baffle 19. During the rotation, the connecting rod 20 can enter the placement slot to avoid affecting the rotation of the baffle 19.

[0028] To further clarify, the aforementioned fixed connection should be interpreted broadly unless otherwise explicitly specified and limited. For example, it may be welding, gluing, or integral molding, or other conventional methods well known to those skilled in the art.

[0029] A heat treatment method for ductile iron manhole covers after casting, achieved in a heat treatment furnace, includes the following steps: S1: Extend the material plate out of the heat treatment furnace body, rotate the rotating support plate upward and place it in the positioning frame, then connect the connecting rod through the baffle and connect it to the upright plate to provide a locking effect for the rotating support plate, and insert the insertion rod through the upright plate and insert it into the rotating support plate.

[0030] S2: Push or hoist the shelf with the manhole cover onto the supported material plate, and ensure that the shelf is centered on the material plate. Push the limiting frame to slide along the translation groove so that its inner wall and the outer contour of the shelf maintain a uniform gap.

[0031] S3: The forklift slowly pushes the slide plate along the chute into the heat treatment furnace. During the movement, the mounting base moves to the left. Because the toothed disc meshes with the toothed plate fixed on the furnace body, it drives the rotating rod to rotate counterclockwise. The actuating plate on the rotating rod rotates accordingly, pushing the horizontal plate and the insert rod to the left, causing the insert rod to exit from the hole in the vertical plate and the rotating support plate. The rotating support plate automatically unlocks. As the slide plate continues to push inward, the left end of the connecting rod contacts the horizontal bar fixed on the furnace body. Under the obstruction of the horizontal bar, the connecting rod is pushed to the right and disengaged from the vertical plate. At this time, the rotating support plate is completely unlocked and rotates to the right around the support axis under its own weight, gradually disengaging from below the positioning frame and returning to the non-interference position.

[0032] S4: Continue pushing the slide plate until the material placement plate and its shelf are fully inside the predetermined position of the heat treatment furnace body. Close the furnace door and heat treat the manhole cover according to the set heat treatment process curve. After the heat treatment process is completed, open the furnace door and use a forklift to pull the slide plate outward to move the material placement plate and the heat-treated manhole cover out of the furnace. When the slide plate moves outward to a longer extension section, the rotating support plate can be manually or assisted to rotate upward to the support position and insert the insertion rod for temporary fixation in preparation for the next loading.

[0033] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and inventive concept of this application, should be included within the scope of protection of this application.

Claims

1. A heat treatment furnace for ductile iron manhole covers after casting, comprising a furnace body (1), wherein a sliding groove (2) is provided inside the furnace body (1), characterized in that: A matching slide plate (3) is slidably installed in the chute (2). A material placement plate (4) is fixedly connected to the top of the slide plate (3). Two transverse grooves are opened on the right side wall of the heat treatment furnace body (1). A balance bar (7) is slidably installed in each of the two transverse grooves. A mounting base (8) is fixedly connected to the right end of the two balance bars (7). A support shaft is rotatably installed on the top of the mounting base (8). A rotating support plate (16) is fixedly installed on the top of the support shaft. A positioning frame (6) is fixedly connected to the bottom of the slide plate (3). The mounting base (8) A vertical plate (13) is fixedly connected to the top of the heat treatment furnace body (1). A horizontally movable insert rod (14) is provided on the left side of the vertical plate (13). A rotating rod (9) is rotatably installed on the top of the mounting base (8) through a bearing. A toothed disc (10) and a toggle plate (12) are fixedly connected to the outer wall of the rotating rod (9). A toothed plate (11) that meshes with the toothed disc (10) is fixedly connected to the right outer wall of the heat treatment furnace body (1). A horizontal plate (15) is fixedly connected to the left end of the insert rod (14). The horizontal plate (15) is located on the rotation path of the toggle plate (12).

2. The heat treatment furnace for ductile iron manhole covers according to claim 1, characterized in that, The top of the mounting base (8) is fixedly connected to a protrusion (17), and a rotating shaft (18) is rotatably mounted on the top of the protrusion (17). A baffle (19) is fixedly connected to the outer wall of the rotating shaft (18). Both the baffle (19) and the upright plate (13) are provided with transverse through holes, and a connecting rod (20) is movably inserted into the through hole of the baffle (19).

3. The heat treatment furnace for ductile iron manhole covers after casting according to claim 1, characterized in that, A crossbar (21) is fixedly connected to the outer right side of the heat treatment furnace body (1). When the connecting rod (20) passes through the through holes of the baffle (19) and the vertical plate (13) at the same time, the connecting rod (20) and the crossbar (21) are in a coaxial state.

4. The heat treatment furnace for ductile iron manhole covers after casting according to claim 1, characterized in that, The mounting base (8) has a placement slot on its right side, and the top of the placement slot is in an open state.

5. The heat treatment furnace for ductile iron manhole covers after casting according to claim 1, characterized in that, A connecting rope connects the left side of the horizontal plate (15) and the vertical plate (13).

6. The heat treatment furnace for ductile iron manhole covers after casting according to claim 2, characterized in that, A connecting piece is fixedly connected to the right end of the docking rod (20), and a connecting rope is connected between the connecting piece and the baffle (19).

7. The heat treatment furnace for ductile iron manhole covers according to claim 1, characterized in that, The material placement plate (4) has translation grooves on its front and rear sides respectively, and each translation groove has a slider slidably installed in it. A limit frame (5) is fixedly connected between the two sliders.

8. A method for implementing a post-casting heat treatment furnace for ductile iron manhole covers using the equipment described in any one of claims 1-7, characterized in that, Includes the following steps: S1: Extend the material plate (4) out of the heat treatment furnace body (1), rotate the rotating support plate (16) upward and place it in the positioning frame (6), then pass the connecting rod (20) through the baffle (19) and connect it to the upright plate (13) to provide a locking effect for the rotating support plate (16), and insert the insertion rod (14) through the upright plate (13) and insert it into the rotating support plate (16). S2: Push or hoist the shelf with the manhole cover onto the supported material plate (4), and ensure that the shelf is centered on the material plate (4). Push the limiting frame (5) to slide along the translation groove so that its inner wall and the outer contour of the shelf maintain a uniform gap. S3: The forklift slowly pushes the slide plate (3) along the slide groove (2) into the heat treatment furnace. During the movement, the mounting base (8) moves to the left. Because the toothed disc (10) meshes with the toothed plate (11) fixed on the furnace body, it drives the rotating rod (9) to rotate counterclockwise. The actuating plate (12) on the rotating rod (9) rotates accordingly, pushing the horizontal plate (15) and the insert rod (14) to the left, so that the insert rod (14) retracts from the hole in the vertical plate (13) and the rotating support plate (16). When the rotating support plate (16) is released, the sliding plate (3) continues to push inward, and the left end of the connecting rod (20) contacts the crossbar (21) fixed on the furnace body. Under the blocking action of the crossbar (21), the connecting rod (20) is pushed to the right and disengaged from the vertical plate (13). At this time, the rotating support plate (16) is completely unlocked and rotates to the right around the support axis under its own weight, gradually disengaging from below the positioning frame (6) and returning to the non-interference position. S4: Continue pushing the slide plate (3) until the material plate (4) and the shelf on it are fully inside the predetermined position of the heat treatment furnace body (1), close the furnace door, heat treat the manhole cover according to the set heat treatment process curve, after the heat treatment process is completed, open the furnace door, use a forklift to pull the slide plate (3) outward, and move the material plate (4) and the heat-treated manhole cover carried out of the furnace. When the slide plate (3) moves outward to a long extension section, the rotating support plate (16) can be manually or assisted to rotate upward to the support position and insert the insertion rod (14) for temporary fixation in preparation for the next loading.

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