A furnace bottom plate for a compressor blade forging automatic rotary hearth furnace

Abstract

The application discloses a furnace bottom plate for automatic converter bottom furnace of compressor blade forging, and belongs to the technical field of compressor blade forging manufacturing of an aero-engine. The furnace bottom plate comprises six split furnace bottom plates which are spliced into an annular structure along a circumferential direction, and six locking blocks which are arranged between side walls of adjacent split furnace bottom plates. The locking block is a tenon structure which extends along a radial direction and is left-right symmetrical. An expansion joint with a length of 3mm is reserved between a matching surface of the tenon structure and a mortise, and is used for compensating high-temperature thermal expansion. The application forcibly limits the relative displacement of adjacent split furnace bottom plates through the clamping and matching of the locking block and the mortise, solves the problem that the positioning of a forging deviates due to accumulated errors of gaps under a high-temperature rotating working condition of the split furnace bottom plate, guarantees the grabbing precision of a mechanical hand, simultaneously considers the compensation of thermal expansion, and the single split furnace bottom plate can be independently replaced through a limited-size maintenance furnace door, so that the maintenance is convenient.

Description

Technical Field

[0001] This invention relates to the field of aero-engine compressor blade forging technology, specifically to a furnace bottom plate for an automated rotary hearth furnace for compressor blade forging. Background Technology

[0002] In the forging process of aero-engine compressor blades, the blanks need to be precisely heated in a rotary hearth furnace. The main body of the rotary hearth furnace is a closed annular furnace body with a rotatable bottom plate, allowing for continuous production. To meet both maintenance and production needs, the furnace body typically has two openings with different functions at the front and rear, including... (1) Repair furnace door: used for furnace internal inspection and furnace bottom plate replacement. Its size is 500×400mm to minimize the heat loss of the furnace body and ensure the uniformity of furnace temperature.

[0003] (2) Working furnace door: used for putting in and taking out forgings. Its size is 300×300mm, which meets the operating space of the robot or manual clamping of forgings.

[0004] During production, forgings are loaded through the working furnace door, driving the furnace bottom to rotate one station, transferring the forging into the heating zone inside the furnace. This process is repeated until the furnace bottom plate at the first station rotates 360° back to the working furnace door, at which point the forging on it has completed its entire heating cycle, and then it is unloaded for forging. Because the maintenance furnace door has fixed and limited dimensions, the furnace bottom plate cannot be a monolithic structure and must be designed in sections. Furthermore, the furnace bottom plate has a lifespan of approximately one year, making it a high-consumption component. When the furnace bottom plate is damaged due to high-temperature creep or other reasons, maintenance personnel only need to replace it piece by piece through the maintenance furnace door, without disassembling the entire furnace body, thus greatly reducing maintenance difficulty and costs.

[0005] However, the practical application of segmented furnace bottom plates has the following drawbacks: under the effects of rotation and high-temperature expansion, the gap between adjacent furnace bottom plates will change unevenly. When the furnace bottom plate carrying the forging rotates back to the working furnace door, if its angle shifts due to accumulated gap errors, it will cause changes in the positioning of the forging at the workstation, making it difficult for the robotic arm to grasp or remove the forging, seriously affecting the continuous operation efficiency of the automated production line and the stability of forging quality.

[0006] To address the positioning accuracy issues caused by uneven gaps in modular splicing structures during operation, several solutions exist in existing technologies. For example, Chinese utility model patent CN210468132U discloses a multi-lobed carbon fiber antenna reflector with interchangeable panel units, comprising multiple reflective fan lobes. These fan lobes combine to form a reflective surface, which includes a central reflective surface. The fan lobes are evenly distributed around the center of the central reflective surface, which is located at its center. Positioning connecting plates extending from the apex of the fan lobes fit into pre-reserved slots on the central reflective surface. A positioning connecting mechanism is located above the slots to press the positioning connecting plates together. This mechanism uses a spring to apply vertical pressure to limit and fix the clamps. This positioning connecting mechanism features rapid assembly and disassembly, high positioning accuracy with repeated assembly and disassembly, and ease of mass production. It enables interchangeability of antenna panel units and improves the maintainability of the antenna reflector.

[0007] The aforementioned solution, through the cooperation of the segmented structure and the central positioning component, solves the problems of ease of assembly and disassembly and repeatability of the modular splicing structure under normal temperature conditions. However, for the application environment of rotary hearth furnace bottom plates, which operate under high-temperature conditions, the thermal expansion effect of the material is significant, and when the gaps are uneven, expansion and compression occur between the blocks, making the stress conditions more complex. Therefore, there is an urgent need for a furnace bottom plate structure that can ensure the overall positioning accuracy and structural stability of the modular furnace bottom plate under high-temperature rotation conditions, while also maintaining the replaceability of individual pieces under the constraint of limited furnace door dimensions for maintenance. Summary of the Invention

[0008] The purpose of this invention is to provide a furnace bottom plate for an automated rotary hearth furnace for compressor blade forging, in order to solve the technical problems in the prior art, where, under the premise of being limited by the size of the furnace door for maintenance, a segmented design must be adopted, the segmented spliced ​​furnace bottom plate is prone to deformation during heating, and the inconsistent gaps after rotation cause the loading and unloading stations to shift, resulting in low repeatability and inaccurate robot material handling.

[0009] The technical solution of the present invention: a furnace bottom plate for an automated rotary hearth furnace for forging compressor blades, comprising several segmented furnace bottom plates, wherein multiple segmented furnace bottom plates are sequentially spliced ​​along the circumferential direction to form a whole furnace bottom plate with an annular structure, and locking blocks are provided between the side walls of two adjacent segmented furnace bottom plates for locking and connecting the two adjacent segmented furnace bottom plates. The locking block is a radially extending and symmetrical tenon structure. On both sides of each segment of the furnace bottom plate, there are tenons that match the shape of the tenon structure. An expansion joint is reserved between the mating surfaces of the tenon structure and the tenon to compensate for high-temperature thermal expansion.

[0010] Furthermore, the segmented furnace bottom plate consists of six pieces, each of which is a fan-shaped arc structure at a 60-degree angle.

[0011] Furthermore, the locking block includes a main body and locking parts symmetrically arranged on both sides of the main body. The main body is a protrusion extending in the radial direction, and the locking part is a block-shaped structure with an arc transition at the end. An arc transition surface is provided at the connection between the main body and the locking part.

[0012] Furthermore, the top height of the main body is higher than the top height of the locking part.

[0013] Furthermore, symmetrical tenons are provided on the radial positions of the two side walls of each segmented furnace bottom plate near the center, and the structure of the tenons is adapted to the structure of the locking part.

[0014] Furthermore, the main outline of the tenon groove is a semi-circular arc, with symmetrical right-angle limiting steps at both ends. The right-angle limiting steps are set outward, forming an overall groove structure similar to an "Ω" shape.

[0015] Furthermore, the expansion joint reserved between the tenon structure and the mating surface of the mortise is 3mm.

[0016] The beneficial effects of this invention are: (1) Improve positioning accuracy: By adding locking blocks between adjacent furnace bottom plates, the relative displacement is forcibly limited by the tenon and mortise structure, which effectively solves the problem of loss of positioning accuracy caused by the block design and the problem of uneven gap caused by the rotation and high temperature expansion of the furnace bottom plate. This ensures the stability of the overall structure of the furnace bottom plate and meets the material handling requirements of the robot arm that can accurately position and grasp the forgings.

[0017] (2) Thermal expansion compensation: A reasonable gap is reserved between the furnace bottom plate and the locking block, which not only ensures positioning accuracy, but also reserves space for high-temperature thermal expansion, avoiding the furnace bottom plate warping or jamming due to thermal stress.

[0018] (3) Easy to maintain and compliant with military standards: The structure does not change the original design of 6 segmented furnace bottom plates, and still maintains the convenience of replacing individual furnace bottom plates through the limited-size maintenance furnace door. At the same time, the structure enhances the stability of the furnace bottom plate and meets the strict requirements for the effective heating zone and temperature uniformity of Class III furnaces in "GJB509 Heat Treatment Process Quality Control" and "HB5425 Test Method for Effective Heating Zone of Heat Treatment Furnace for Aerospace Parts". Attached Figure Description

[0019] To more clearly illustrate the technical solutions in the specific embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0020] Figure 1This is a top view schematic diagram of the overall structure of the furnace bottom plate for the automated rotary hearth furnace for compressor blade forging according to the present invention; Figure 2 for Figure 1 The main view of section A; Figure 3 for Figure 2 AA section view; Figure 4 This is a three-dimensional view of the locking block of the present invention; Figure 5 This is a front view of the locking block of the present invention; Figure 6 This is a side view of the locking block of the present invention; Figure 7 This is a top view of the locking block of the present invention. Detailed Implementation

[0021] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, it should not be construed that the scope of the subject matter of the present invention is limited to the following embodiments. All modifications, substitutions and alterations made based on ordinary technical knowledge and common practices in the art without departing from the above-described technical concept of the present invention are included within the scope of the present invention.

[0022] The present invention relates to a furnace bottom plate for an automated rotary hearth furnace for compressor blade forging, comprising six segmented plates evenly arranged along the circumference; a locking block is provided between the side walls of two adjacent plates; the locking block is a radially extending, symmetrical tenon structure, and both side walls of the segmented plates are provided with tenons that match the shape of the tenons; a 3mm expansion gap is reserved between the mating surfaces of the tenons and the tenons.

[0023] As the furnace bottom rotates, the driving force is transmitted through locking blocks, constraining the six segmented plates to maintain a uniform spacing and posture. After the workstation rotates 360° to complete heating, it returns to the working furnace door, its position remaining unchanged, allowing the robotic arm to easily grasp it. When the furnace bottom plate needs repair or replacement, since the outer contour dimensions of a single plate are smaller than the opening size of the repair furnace door, it can be replaced independently only through the repair furnace door.

[0024] The embodiment provides a furnace bottom plate for an automated rotary hearth furnace for compressor blade forging, specifically designed for use in the rotary hearth heating furnace of an automated production line for forging aero-engine compressor blades.

[0025] like Figure 1 As shown, the furnace bottom plate in this embodiment consists of six segmented furnace bottom plates and six locking blocks. The six segmented furnace bottom plates are sequentially spliced ​​along the circumference to form a complete annular furnace bottom plate structure. A locking block is provided between the side walls of two adjacent segmented furnace bottom plates to lock the adjacent segmented furnace bottom plates together, so that the six segmented furnace bottom plates form an integral and stable annular working surface.

[0026] The structure of the segmented furnace bottom plate: Each segmented furnace bottom plate has a fan-shaped arc structure with a central angle of 60 degrees. The outer contour dimensions of a single segmented furnace bottom plate are designed such that the maximum radial length is less than the opening size of the maintenance furnace door by 500 mm, and the maximum width in the arc direction is less than the opening size of the maintenance furnace door by 400 mm. This dimensional design ensures that when replacement is needed, a single segmented furnace bottom plate can be independently removed and installed through the maintenance furnace door without disassembling the entire furnace body.

[0027] like Figure 1 Combination Figure 2 and Figure 3 As shown, a tenon groove is provided on each side wall of each segmented furnace bottom plate at a radial position near the center (specifically, approximately 1 / 4 of the radial distance from the center). This tenon groove is used to cooperate with the locking block to connect and position adjacent furnace bottom plates. The specific structure of the tenon groove is as follows: the main outline is semi-circular, and symmetrical right-angle limiting steps are provided at the openings at both ends of the semi-circular groove. The step surfaces of the two right-angle limiting steps are both set outward, so that the cross-sectional outline of the entire tenon groove forms a groove structure similar to "Ω".

[0028] Structure of the locking block: as follows Figures 4-7 As shown, each locking block is a symmetrical tenon structure extending radially along the furnace bottom plate. Specifically, each locking block includes a main body and two locking parts symmetrically arranged on both sides of the main body.

[0029] The main body, located at the center of the locking block, is a strip-shaped protrusion extending radially. Two locking parts are integrally formed on the left and right sides of the main body, each a block structure with rounded ends. Smooth, curved transition surfaces are provided at the junctions between the main body and the locking parts on both sides to avoid stress concentration. Viewed radially, the top height of the main body is higher than the top height of the locking parts on both sides, allowing the main body to play a primary role in load-bearing and limiting the locking block after it is embedded in the tenon grooves of the segmented furnace bottom plates on both sides.

[0030] During assembly, each locking block simultaneously engages with the mortises on the opposite sidewalls of two adjacent segmented furnace bottom plates. The two locking parts of the locking block respectively enter the mortises of the two segmented furnace bottom plates, with the rounded transition ends of the locking parts aligning with the semi-circular main contour of the mortises, achieving initial radial and circumferential positioning. Simultaneously, the engaging engagement of the locking parts with the right-angle limiting steps at both ends of the mortises forcibly limits the relative displacement of the two adjacent segmented furnace bottom plates in the circumferential and radial directions, eliminating angular offsets caused by accumulated gap errors.

[0031] A 3mm expansion gap is uniformly reserved between the tenon structure of the locking block and each mating surface of the tenon groove of the segmented furnace bottom plate. This expansion gap is a pre-reserved gap under normal temperature assembly conditions. When the furnace bottom plate is operating under high temperature conditions, the components will expand due to heat. The reserved 3mm expansion gap can be filled by the expansion, providing compensation space for thermal expansion, thereby avoiding warping and deformation of the furnace bottom plate caused by thermal stress concentration or jamming caused by interference fit.

[0032] In actual production operations, the furnace bottom plate of this embodiment is installed at the bottom of the rotary hearth furnace. When the drive mechanism drives the furnace bottom to rotate, the rotational driving force is transmitted between the segmented furnace bottom plates through the locking blocks. Because the locking blocks and tenons constrain the relative displacement of adjacent segmented furnace bottom plates, the six segmented furnace bottom plates maintain a uniform spacing and posture during rotation, and will not experience angular displacement due to operating vibration or changes in gaps.

[0033] When the segmented furnace bottom plate carrying the forging rotates 360° with the furnace bottom to complete the entire heating cycle and returns to the working furnace door, the position of the forging at this station remains consistent with its position during loading, without any positioning deviation caused by the offset of the furnace bottom plate. The robotic arm can smoothly pick up the forging and transfer it to the forging station at the preset coordinate position, ensuring the continuous operating efficiency of the automated production line.

[0034] When the furnace bottom plate needs to be replaced due to creep or damage caused by prolonged high-temperature use, maintenance personnel only need to open the maintenance furnace door, pull out the individual furnace bottom plate to be replaced radially to complete the disassembly, and then push the new furnace bottom plate radially in, so that its side wall tenon grooves mate with the adjacent locking blocks to complete the installation. The entire process does not require disassembling the furnace body, and single-piece replacement is convenient and quick.

[0035] The furnace bottom plate structure in this embodiment, through the above-mentioned mortise and tenon connection and thermal expansion gap design, not only meets the strict requirements of GJB509B "Quality Control of Heat Treatment Process" and HB 5425 "Test Method for Effective Heating Zone of Heat Treatment Furnace for Aerospace Parts" for the effective heating zone and temperature uniformity of Class III furnaces, but also effectively solves the problem of loss of positioning accuracy of segmented furnace bottom plates under high temperature rotation conditions, taking into account both maintenance convenience and long-term operational stability.

[0036] The furnace bottom plate for an automated rotary hearth furnace for compressor blade forging provided by this invention has been described in detail above. Specific examples have been used to illustrate the structure and working principle of this invention. The descriptions of the embodiments above are only for the purpose of helping to understand the method and core ideas of this invention. It should be noted that those skilled in the art can make several improvements and modifications to this invention without departing from the principles of this invention, and these improvements and modifications also fall within the scope of protection of the claims of this invention.

Claims

1. A furnace bottom plate for an automated rotary hearth furnace for forging compressor blades, characterized in that: It includes several segmented furnace bottom plates, and multiple segmented furnace bottom plates are spliced ​​together in a circular direction to form a whole furnace bottom plate with a ring structure. Locking blocks are provided between the side walls of two adjacent segmented furnace bottom plates to lock the two adjacent segmented furnace bottom plates together. The locking block is a radially extending and symmetrical tenon structure. On both sides of each segment of the furnace bottom plate, there are tenons that match the shape of the tenon structure. An expansion joint is reserved between the mating surfaces of the tenon structure and the tenon to compensate for high-temperature thermal expansion.

2. The furnace bottom plate for an automated rotary hearth furnace for compressor blade forging according to claim 1, characterized in that: The segmented furnace bottom plate consists of six pieces, each of which is a fan-shaped arc structure at a 60-degree angle.

3. The hearth plate for an automated rotary hearth furnace for compressor blade forging according to claim 1, characterized in that: The locking block includes a main body and locking parts symmetrically arranged on both sides of the main body. The main body is a protrusion extending in the radial direction, and the locking part is a block-shaped structure with an arc transition at the end. An arc transition surface is provided at the connection between the main body and the locking part.

4. The hearth plate for an automated rotary hearth furnace for compressor blade forging according to claim 3, characterized in that: The top height of the main body is higher than the top height of the locking part.

5. The hearth plate for an automated rotary hearth furnace for compressor blade forging according to claim 1, characterized in that: Symmetrical tenons are provided on the radial positions of the two side walls of each segmented furnace bottom plate near the center, and the structure of the tenons is adapted to the structure of the locking part.

6. The hearth plate for an automated rotary hearth furnace for compressor blade forging according to claim 5, characterized in that: The main outline of the tenon groove is a semi-circular arc, with symmetrical right-angle limiting steps at both ends. The right-angle limiting steps are set outward, forming an overall groove structure similar to "Ω".

7. The hearth plate for an automated rotary hearth furnace for compressor blade forging according to claim 1, characterized in that: The expansion joint reserved between the tenon structure and the mortise groove is 3mm.

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