Sand casting mold for water inlet elbow of engine

Abstract

The utility model relates to the technical field of mold manufacturing, in particular to an engine water inlet elbow sand mold casting mold, which comprises a metal mold with a square outer frame structure and a sand core with a square inner frame structure, the metal mold and the sand core are respectively composed of an upper mold and a lower mold which are horizontally folded, and the positions of parting surfaces are consistent. One metal mold and one sand core form a combined unit, at least four sand boxes can be arranged in each sand box, and accurate matching of the upper mold and the lower mold is achieved by sharing positioning pins and positioning holes. Compared with the prior art, through the integrated design of the square-shaped frame and the multiple combination units, the space utilization rate of the sand box is remarkably improved.

Description

Technical Field

[0001] This utility model relates to the field of mold manufacturing technology, and in particular to a sand casting mold for an engine water inlet elbow. Background Technology

[0002] In the casting industry, metal molds and sand cores are the core process equipment for constructing casting forming systems. Metal molds, made of metallic materials, possess excellent high-temperature erosion resistance, high strength, and wear resistance. Their good thermal conductivity accelerates the solidification process of castings, promotes grain refinement, and significantly improves the mechanical properties of castings. Therefore, they are widely used in the mass production of non-ferrous metal castings such as aluminum alloys and magnesium alloys. Sand cores are mainly used to form complex internal structures in castings, such as channels, cavities, and irregularly shaped internal cavities. Through precise sand proportioning and molding processes, they can meet the forming requirements of high-precision internal cavity structures.

[0003] Taking an engine water inlet elbow as an example, its typical structure includes orthogonally arranged horizontal and vertical pipes. The horizontal pipe has a circular cross-section, and the vertical pipe has a rounded square cross-section. The two transition at the intersection, and a connecting flange is installed at the free end of the vertical pipe. Currently, in the casting process of this type of part, the metal mold 100 and sand core 200 used are as follows... Figure 1 As shown, the traditional single-piece, single-model design is commonly used. This design pattern has the following technical problems:

[0004] 1. Limitations in space utilization and production efficiency: Due to the single-piece, single-model mold layout, the number of workpieces that can be arranged in a single sand box during sand casting is extremely limited, resulting in insufficient release of equipment capacity. In large-scale production scenarios, this problem further exacerbates the frequency of mold replacement and the cost of sand box usage, making it difficult to meet the demands of modern manufacturing for efficient casting.

[0005] 2. Filling Defects and Quality Stability Issues: Due to the transition of the cross-section from a circle to a rounded square and the irregular structure at the flange of the inlet elbow, the molten metal is prone to insufficient filling in certain areas during the filling process due to increased flow resistance. Although existing metal mold designs incorporate traditional risers, the limited simplicity of the mold structure makes it difficult to completely solve the problem of insufficient flowability in complex structures. Defects such as cold shuts and incomplete filling often occur, leading not only to increased scrap rates but also adversely affecting the sealing and pressure-bearing performance of the engine inlet elbow. Utility Model Content

[0006] This invention aims to solve the problems of severe material waste, long production cycles, and / or high costs in the existing engine cold core mold processing. The mold structure is optimized through a modular, split design. The specific technical solution is as follows:

[0007] A sand casting mold for an engine water inlet elbow includes a metal mold and a sand core. Unlike existing technologies, the metal mold has an overall U-shaped outer frame structure, including an upper mold and a lower mold arranged horizontally, forming a horizontal parting surface along the middle of the metal mold's height. The upper and lower molds, when aligned, form a cavity that matches the shape of the engine water inlet elbow. The sand core has an overall U-shaped inner frame structure, including an upper core mold and a lower core mold arranged horizontally, with their horizontal parting surface aligned with the horizontal parting surface of the metal mold. The upper and lower core molds, when aligned, form a core cavity that matches the inner cavity of the engine water inlet elbow. One metal mold and one sand core form one assembly unit, and at least four assembly units can be arranged in a single sand box. All assembly units achieve precise matching of the upper and lower molds through shared locating pins and locating holes.

[0008] Furthermore, the U-shaped outer frame of the metal mold is formed by the mating of an upper mold and a lower mold: the upper mold includes two opposing upper semi-circular tube forming parts and two opposing upper semi-square tube forming parts, the upper semi-circular tube forming parts corresponding to the upper and lower horizontal edges of the U-shaped outer frame, and the upper semi-square tube forming parts forming the left and right vertical edges of the U-shaped outer frame; the lower mold includes two opposing lower semi-circular tube forming parts and two opposing lower semi-square tube forming parts, the lower semi-circular tube forming parts corresponding to the upper and lower horizontal edges of the U-shaped outer frame, and the lower semi-square tube forming parts forming the left and right vertical edges of the U-shaped outer frame; the axes of the upper semi-circular tube forming parts are orthogonal to the adjacent upper semi-square tube forming parts and the forming surfaces are smoothly transitioned, the axes of the lower semi-circular tube forming parts are orthogonal to the adjacent lower semi-square tube forming parts and the forming surfaces are smoothly transitioned; the U-shaped inner frame of the sand core is formed by the mating of an upper core mold and a lower core mold. The upper core mold includes two opposing upper semi-circular core sections and two opposing upper semi-square core sections. The upper semi-circular core sections correspond to the upper and lower horizontal edges of the U-shaped inner frame, and the upper semi-square core sections correspond to the left and right vertical edges of the U-shaped inner frame. The lower core mold includes two opposing lower semi-circular core sections and two opposing lower semi-square core sections. The lower semi-circular core sections correspond to the upper and lower horizontal edges of the U-shaped inner frame, and the lower semi-square core sections correspond to the left and right vertical edges of the U-shaped inner frame. The axes of the upper semi-circular core sections are orthogonal to those of the adjacent upper semi-square core sections, and their forming surfaces are smoothly transitioned. The axes of the lower semi-circular core sections are also orthogonal to those of the adjacent lower semi-square core sections, and their forming surfaces are smoothly transitioned.

[0009] Furthermore, the upper mold includes two first runner plates extending outward from the upper semi-circular tube forming part.

[0010] Furthermore, the lower surface of the first runner plate is coplanar with the parting surface and its thickness gradually increases from the inside to the outside.

[0011] Furthermore, the middle part of the upper semi-circular tube forming part and the lower semi-circular tube core forming part extends left and right along the axial direction to form the upper semi-circular tube additional forming part and the lower semi-circular tube additional forming part.

[0012] Furthermore, the upper mold includes two alternating upper flange forming parts located in the middle of the upper square tube forming part; the lower mold includes two alternating lower flange forming parts located in the middle of the lower square tube forming part.

[0013] Furthermore, the upper flange forming parts inside and outside the upper square tube forming part are connected together by upper flange connecting pieces; the lower flange forming parts inside and outside the lower square tube forming part are connected together by lower flange connecting pieces.

[0014] Furthermore, the upper mold includes a second sprue plate protruding forward from the middle of the upper square tube forming part; the lower mold includes a third sprue plate protruding backward from the middle of the lower square tube forming part.

[0015] Furthermore, the second and third gating sections are shaped like a sloping roof, with the middle section being higher and the left and right sides being lower.

[0016] Furthermore, the left and right sides of the second runner plate are integrated with the upper flange forming part, and the left and right sides of the third runner plate are integrated with the lower flange forming part.

[0017] Compared with the prior art, the present invention has the following beneficial technical effects:

[0018] In terms of improving production efficiency, it breaks through the spatial limitations of traditional single-piece, single-mold designs. By designing the metal mold and sand core as nested combination units with a U-shaped outer and inner frame, at least four combination units can be arranged in a single sand box, enabling the production of four engine inlet elbows in a single casting, significantly improving the sand box space utilization rate compared to existing technologies. At the same time, all combination units achieve precise matching between the upper and lower molds through shared locating pins and locating holes, avoiding the repeated debugging problems caused by positioning deviations in traditional molds, shortening mold assembly time, significantly reducing mold replacement frequency and sand box usage costs, and effectively meeting the demand for high-efficiency casting in large-scale production.

[0019] In terms of casting quality optimization, the U-shaped frame structure provides a smooth path for molten metal filling. Within the outer frame of the metal mold and the inner frame of the sand core, the orthogonally arranged horizontal pipes (circular cross-sections) and vertical pipes (rounded square cross-sections) have orthogonal axes and smooth transitions, significantly reducing the flow resistance of the molten metal in the cross-section transition zone and flange connections. This effectively reduces filling defects such as cold shuts and incomplete pouring, improving the integrity of the casting. Furthermore, the horizontal parting surfaces of the sand core and the metal mold are aligned, ensuring precise alignment when the inner and outer frames are closed. This avoids uneven wall thickness or contour deviations in the casting caused by parting surface misalignment, especially ensuring the connection accuracy of the orthogonal pipe body of the inlet elbow, playing a crucial role in improving the sealing and pressure-bearing performance of the casting.

[0020] In terms of structural innovation and process adaptability, the metal mold outer frame and the sand core inner frame form a synergistic system of "outer contour forming + inner cavity structure forming". The metal mold utilizes the high thermal conductivity of metal materials to accelerate casting solidification, promote grain refinement, and improve the mechanical properties of the casting; the sand core, through precise molding sand ratio and molding process, accurately constructs complex inner cavity structures, solving the problem that traditional molds cannot simultaneously achieve efficient solidification and complex inner cavity forming. At the same time, the modular design of the combined units brings standardization advantages. The unified positioning system and symmetrical frame structure facilitate standardized mold production and rapid replacement, reduce mold maintenance costs, and provide a structural basis for subsequent mold modifications for similar parts, further improving process adaptability.

[0021] In summary, this utility model, through the integrated design of a U-shaped frame structure and multiple combination units, effectively solves the problems of low production efficiency, numerous filling defects, and high costs in the prior art without significantly increasing the complexity of the mold. It is especially suitable for casting engine water inlet elbows with orthogonal cross-section pipes and complex internal cavity structures, and has the dual technical advantages of high-efficiency production and high-quality molding. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the metal mold used for the water inlet elbow of an existing cast engine.

[0023] Figure 2 A schematic diagram of the structure of the sand core used for the water inlet elbow of an existing cast engine.

[0024] Figure 3 This is a schematic diagram of the structure of the metal mold used for casting engine water inlet elbows according to this utility model.

[0025] Figure 4 for Figure 3 A structural diagram from another perspective.

[0026] Figure 5 This is a schematic diagram of the sand core used for casting engine water inlet elbows according to this utility model. Detailed Implementation

[0027] like Figure 3-5 The sand casting mold for an engine water inlet elbow, as shown, includes a metal mold 100 and a sand core 200. The metal mold 100 has an overall U-shaped outer frame structure, including an upper mold 101 and a lower mold 102 arranged horizontally, forming a horizontal parting surface along the middle of the height direction of the metal mold. The upper mold 101 and the lower mold 102, when engaged, form a cavity that matches the shape of the engine water inlet elbow. The sand core 200 has an overall U-shaped inner frame structure, including an upper core mold 201 and a lower core mold 202 arranged horizontally, with its horizontal parting surface aligned with the horizontal parting surface of the metal mold 100. The upper core mold 201 and the lower core mold 202, when engaged, form a core cavity that matches the inner cavity of the engine water inlet elbow. One metal mold 100 and one sand core 200 form one combined unit, and at least four combined units can be arranged in a single sand box. All combined units achieve precise matching of the upper and lower molds through shared locating pins and locating holes. This embodiment solves the problems of low efficiency, poor precision, and high cost of traditional single-piece casting by efficiently utilizing the space of the U-shaped frame, accurately coordinating the forming of inner and outer contours, rapidly adapting the modular structure, and coordinating the positioning system from the underlying logic of mold design. Its core principle lies in transforming the forming requirements of complex elbows into a standardized combination of frame modules. Through structural symmetry, modular components, and precise positioning design, it achieves simultaneous improvement in production efficiency, casting quality, and process flexibility, making it suitable for multi-variety, large-scale sand casting production scenarios.

[0028] In another preferred embodiment, the U-shaped outer frame of the metal mold 100 is formed by the mating of an upper mold 101 and a lower mold 102: the upper mold 101 includes two opposing upper semi-circular tube forming parts 1011 and two opposing upper semi-square tube forming parts 1012, the upper semi-circular tube forming parts 1011 corresponding to the upper and lower horizontal sides of the U-shaped outer frame, and the upper semi-square tube forming parts 1012 forming the left and right vertical sides of the U-shaped outer frame; the lower mold 102 includes two opposing lower semi-circular tube forming parts 1021 and two opposing lower semi-square tube forming parts 1022, the lower semi-circular tube forming parts 1021 corresponding to the upper and lower horizontal sides of the U-shaped outer frame, and the lower semi-square tube forming parts 1022 forming the left and right vertical sides of the U-shaped outer frame. The upper semi-circular tube forming part 1011 is orthogonal to the adjacent upper semi-square tube forming part 1012 and the forming surface transitions smoothly; the lower semi-circular tube forming part 1021 is orthogonal to the adjacent lower semi-square tube forming part 1022 and the forming surface transitions smoothly; the U-shaped inner frame of the sand core 200 is formed by the mating of the upper core mold 201 and the lower core mold 202. The upper core mold 201 includes two opposing upper semi-circular core forming parts 2011 and two opposing upper semi-square core forming parts 2012. The upper semi-circular core forming parts 2011 correspond to the upper and lower horizontal sides of the U-shaped inner frame, and the upper semi-square core forming parts 2012 correspond to the left and right vertical sides of the U-shaped inner frame. The lower core mold 202 includes two opposing lower semi-circular core forming parts 2021 and two opposing lower semi-square core forming parts 2022. The lower semi-circular core forming parts 2021 correspond to the upper and lower horizontal sides of the U-shaped inner frame, and the lower semi-square core forming parts 2022 correspond to the left and right vertical sides of the U-shaped inner frame. The upper semi-circular core forming part 2011 is orthogonal to the axis of the adjacent upper semi-square core forming part 2012 and the forming surface is smoothly transitioned. The lower semi-circular core forming part 2021 is orthogonal to the axis of the adjacent lower semi-square core forming part 2022 and the forming surface is smoothly transitioned.

[0029] "Orthogonal axes" describes the geometric relationship of the spatial orientation of the tubes, that is, the center lines (axes) of the two tubes intersect perpendicularly in three-dimensional space (with an included angle of 90°). This relationship is directly determined by the spatial layout of the mold forming part and has no necessary relation to the cross-sectional shape of the tubes (circular, square or other shapes).

[0030] For a square-section tube, its axis is defined as the line of symmetry of the tube's center (i.e., the line connecting the geometric centers of the cross section), which is consistent with the definition of the axis of a circular cross section.

[0031] The mold forming section designs the forming structures of the two tube parts (such as the cavity of a metal mold or the core cavity of a sand core) to arrange them in a perpendicular intersecting layout in space, ensuring that the axes of the formed tubes are naturally orthogonal. For example, the horizontal tube forming section and the vertical tube forming section are perpendicularly connected in the mold, and their center lines are perpendicular at the intersection point. This spatial geometric relationship can be achieved through the mold structure, regardless of whether the cross-section is circular or square.

[0032] The orthogonal layout of the horizontal / vertical forming sections of the upper and lower molds ensures that the axes of the horizontal (circular) and vertical (square) pipes of the elbow intersect precisely perpendicularly, meeting the geometric accuracy requirements for the orthogonal connection of the engine inlet elbow. The smooth transition of the forming surface reduces the resistance to molten metal flow, preventing defects such as eddies and cold shuts in the cross-sectional transition zone during filling, and improving the integrity of the casting outline. The symmetrical design of the upper and lower mold forming sections facilitates rapid alignment during mold closing. Combined with the positioning system, this ensures precise nesting of the cavities and core cavities of the inner and outer frames, guaranteeing uniform casting wall thickness.

[0033] In another preferred embodiment, the upper mold 101 includes two first runner plates 1013 extending outward from the upper semi-circular tube forming portion 1011. The runner plates provide dedicated channels for the molten metal, avoiding direct impact on the cavity wall and reducing splashing and oxide inclusions.

[0034] In another preferred embodiment, the lower surface of the first sprue 1013 is coplanar with the parting surface, and its thickness gradually increases from the inside to the outside. This gradual thickness design (thinner inside, thicker outside) gradually increases the molten metal pressure, ensuring full filling of the distal cavity. The coplanarity of the sprue's lower surface with the parting surface forms a flat, sealing surface with the lower mold during mold closing, preventing molten metal leakage from the joint between the sprue and the parting surface and reducing defects such as flash and burrs.

[0035] In another preferred embodiment, the middle portions of the upper semi-circular tube forming part 1011 and the lower semi-circular tube core forming part 2021 extend axially to the left and right to form an upper semi-circular tube additional forming part 1017 and a lower semi-circular tube additional forming part 1027. The additional forming parts, by reserving machining allowance, combine the "shape-based" approach of casting with the "precision-based" approach of machining, ensuring the basic outline of the casting while providing tolerance for subsequent precision machining. This design is particularly suitable for castings with "high-precision assembly requirements + complex structures," such as engine water inlet elbows. Through the combination of "casting redundancy + machining refinement," a balance between production efficiency and product quality is achieved, representing a key innovation in the upgrade of sand casting molds from "single forming" to "forming-machining integration."

[0036] In another preferred embodiment, the upper mold 101 includes two alternating upper flange forming portions 1014 located in the middle of the upper square tube forming portion 1012; the lower mold 102 includes two alternating lower flange forming portions 1024 located in the middle of the lower square tube forming portion 1022. The alternating flange forming portions (corresponding to the connecting flanges at the free ends of the elbow vertical pipes) ensure the coaxiality of the flanges and vertical pipes, avoiding installation failures caused by flange misalignment. The integrated design of the flange forming portion and the square tube forming portion enhances the wear resistance of the mold at complex flange structures and extends the mold's service life.

[0037] In another preferred embodiment, the upper flange forming parts 1014 inside and outside the upper square tube forming part 1012 are connected as one unit by upper flange connecting pieces 1015; the lower flange forming parts 1024 inside and outside the lower square tube forming part 1022 are connected as one unit by lower flange connecting pieces 1025. This connecting piece design links the dispersed flange forming parts into an integral frame, avoiding mold deformation or localized breakage caused by the pressure of molten metal filling, making it particularly suitable for high-pressure casting scenarios. The connecting piece acts as a rigid support inside the mold, and the auxiliary positioning system ensures precise alignment of the upper and lower mold flange forming parts, reducing misalignment errors at the flange end faces.

[0038] In another preferred embodiment, the upper mold 101 includes a second runner plate 1016 protruding forward from the middle of the upper square tube forming portion 1012; the lower mold 102 includes a third runner plate 1026 protruding rearward from the middle of the lower square tube forming portion 1022. The second runner plate 1016 and the third runner plate 1026 provide shrinkage compensation channels to prevent shrinkage cavities.

[0039] In another preferred embodiment, the second runner 1016 and the third runner 1026 are shaped like a sloping roof, with a higher center and lower sides. The sloping roof shape (higher center and lower sides) guides the molten metal to flow from a higher position to a lower position, facilitating the discharge of gas from the top of the cavity and reducing porosity defects.

[0040] In another preferred embodiment, the left and right sides of the second sprue plate 1016 are integrated with the upper flange forming part 1014, and the left and right sides of the third sprue plate 1026 are integrated with the lower flange forming part 1024. The sprue plates are connected to the flange forming part to form an integrated "sprue-flange" molding structure, which simplifies the mold assembly process, ensures the precise correspondence between the sprue position and the flange structure, and improves the filling efficiency and flange forming quality.

[0041] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A sand casting mold for an engine water inlet elbow, comprising a metal mold (100) and a sand core (200), characterized in that, The metal mold (100) has an overall U-shaped outer frame structure, including an upper mold (101) and a lower mold (102) arranged horizontally, which form a horizontal parting surface along the middle of the height direction of the metal mold; the upper mold (101) and the lower mold (102) together form a cavity that matches the shape of the engine water inlet elbow; the sand core (200) has an overall U-shaped inner frame structure, including an upper core mold (201) and a lower core mold (202) arranged horizontally, whose horizontal parting surface is consistent with the horizontal parting surface of the metal mold (100); the upper core mold (201) and the lower core mold (202) together form a core cavity that matches the inner cavity of the engine water inlet elbow; one metal mold (100) and one sand core (200) form one combined unit, and at least four combined units can be arranged in a single sand box; all combined units achieve precise matching of the upper and lower molds through shared positioning pins and positioning holes.

2. The sand casting mold for an engine water inlet elbow according to claim 1, characterized in that, The metal mold (100) has a U-shaped outer frame formed by the mating of an upper mold (101) and a lower mold (102): The upper mold (101) includes two opposing upper semi-circular tube forming parts (1011) and two opposing upper square tube forming parts (1012), the upper semi-circular tube forming parts (1011) correspond to the upper and lower horizontal sides of the U-shaped outer frame, and the upper square tube forming parts (1012) constitute the left and right vertical sides of the U-shaped outer frame; The lower mold (102) includes two opposing lower semi-circular tube forming parts (1021) and two opposing lower square tube forming parts (1022), the lower semi-circular tube forming parts (1021) correspond to the upper and lower horizontal sides of the U-shaped outer frame, and the lower square tube forming parts (1022) constitute the left and right vertical sides of the U-shaped outer frame. The upper semi-circular tube forming part (1011) is orthogonal to the axis of the adjacent upper semi-square tube forming part (1012) and the forming surface is smoothly transitioned. The lower semi-circular tube forming part (1021) is orthogonal to the axis of the adjacent lower semi-square tube forming part (1022) and the forming surface is smoothly transitioned. The inner frame of the sand core (200) is formed by the mating of the upper core mold (201) and the lower core mold (202): The upper core mold (201) includes two opposing upper semi-circular tube core forming parts (2011) and two opposing upper semi-square tube core forming parts (2012). The upper semi-circular tube core forming parts (2011) correspond to the upper and lower horizontal sides of the inner frame. The upper semi-square tube core forming parts (2012) correspond to the left and right vertical sides of the inner frame. The core mold (202) includes two opposing lower semi-circular core forming parts (2021) and two opposing lower semi-square core forming parts (2022). The lower semi-circular core forming parts (2021) correspond to the upper and lower horizontal sides of the U-shaped inner frame, and the lower semi-square core forming parts (2022) correspond to the left and right vertical sides of the U-shaped inner frame. The upper semi-circular core forming part (2011) is orthogonal to the axis of the adjacent upper semi-square core forming part (2012) and the forming surface is smoothly transitioned. The lower semi-circular core forming part (2021) is orthogonal to the axis of the adjacent lower semi-square core forming part (2022) and the forming surface is smoothly transitioned.

3. The sand casting mold for an engine water inlet elbow according to claim 2, characterized in that, The upper mold (101) includes two first sprue plates (1013) extending outward from the upper semi-circular tube forming part (1011).

4. The sand casting mold for an engine water inlet elbow according to claim 3, characterized in that, The lower surface of the first gating plate (1013) is coplanar with the parting surface and its thickness gradually increases from the inside to the outside.

5. The sand casting mold for an engine water inlet elbow according to claim 2, characterized in that, The middle part of the upper semi-circular tube forming part (1011) and the lower semi-circular tube core forming part (2021) extends left and right along the axial direction to form the upper semi-circular tube additional forming part (1017) and the lower semi-circular tube additional forming part (1027).

6. The sand casting mold for an engine water inlet elbow according to claim 2, characterized in that, The upper mold (101) includes two alternating upper flange forming parts (1014) located in the middle of the upper square tube forming part (1012); the lower mold (102) includes two alternating lower flange forming parts (1024) located in the middle of the lower square tube forming part (1022).

7. The sand casting mold for an engine water inlet elbow according to claim 6, characterized in that, The upper flange forming parts (1014) inside and outside the upper half square tube forming part (1012) are connected as one unit by upper flange connecting piece (1015); the lower flange forming parts (1024) inside and outside the lower half square tube forming part (1022) are connected as one unit by lower flange connecting piece (1025).

8. The sand casting mold for an engine water inlet elbow according to claim 6, characterized in that, The upper mold (101) includes a second sprue plate (1016) protruding forward from the middle of the upper square tube forming part (1012); the lower mold (102) includes a third sprue plate (1026) protruding backward from the middle of the lower square tube forming part (1022).

9. A sand casting mold for an engine water inlet elbow according to claim 8, characterized in that, The second gating plate (1016) and the third gating plate (1026) are shaped like a sloping roof, which is high in the middle and low on the left and right sides.

10. A sand casting mold for an engine water inlet elbow according to claim 8, characterized in that, The left and right sides of the second runner plate (1016) are integrated with the upper flange forming part (1014), and the left and right sides of the third runner plate (1026) are integrated with the lower flange forming part (1024).

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