A method for fixing a through-hole core in a cylinder block molding process

Abstract

A fixing method of through bolt hole core in a cylinder body molding process, the through bolt hole core is used for molding forming the through bolt hole of the cylinder body, characterized by: fixing and placing the through bolt hole fixing core outside the outer mold position of the main mold cavity of the cylinder body during the molding process, pressing on the through bolt hole core, and fixing the through bolt hole core at the predetermined required position by the action of the vertical inclined plane to prevent movement. The invention adopts the mode of combined core to replace the traditional metal positioning plate or core support, fixes the through bolt hole core, and uses the lapping of the inclined plane to firmly combine the through bolt hole fixing core and the through bolt hole core, ensures the reliable fixing of the through bolt hole core during the assembling and pouring process, thereby avoiding the formation of metal inclusion defects of the casting, reducing the risk of product scrap, reducing the repair working hours, improving the quality stability of the product, and reducing the production cost.

Description

Technical Field

[0001] This invention relates to the casting process of marine diesel engine cylinder blocks, specifically to a method for fixing a core through a threaded hole during the cylinder block molding process, belonging to the field of marine diesel engine manufacturing technology. Background Technology

[0002] The cylinder block of a marine diesel engine is a large casting, typically composed of multiple identical cylinder units; such as Figure 1 As shown, the cylinder block 1 is provided with multiple through bolt holes 2 for inserting through bolts during assembly to secure the cylinder head. During the casting process of the cylinder block 1, most manufacturers typically choose to use a through bolt hole core in the sand casting process to create the through bolt holes 2.

[0003] The depth of the through bolt holes 2 in the cylinder block 1 is very deep, therefore the height of the through bolt core 3 is correspondingly high, typically exceeding 2000mm. If the through bolt core 3 is not properly fixed within the sand mold, it will wobble from side to side during the molding and assembly process, causing instability and difficulty in mold assembly. Alternatively, the through bolt core 3 may shift during molten iron pouring, resulting in dimensional deviations in the position of the through bolt holes 2 in the cylinder block 1, leading to product quality issues. Currently, the common method for fixing the through bolt core 3 is to use a metal positioning plate 5 or a core brace for support. Please refer to [link to relevant documentation]. Figure 2 However, both of these fixing methods may cause metal inclusion defects in the cylinder block 1 casting, posing a risk of product scrap. Therefore, in the molding process of cylinder block 1 casting, fixing the through-hole core 3 in the sand mold is a key production point and a technical challenge. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a method for fixing the core of the through-hole screw hole during the cylinder block molding process. By optimizing the core structure, the method solves the problem of fixing the core of the through-hole screw hole during the assembly and casting process, prevents interference of the through bolt during assembly caused by the misalignment of the through-hole screw hole of the cylinder block casting, avoids the formation of metal inclusion defects in the casting, improves the quality stability of the casting, and reduces the risk of product scrap.

[0005] Based on the above objectives, the technical solution adopted by the present invention is as follows: A method for fixing a through-bolt core during cylinder block molding, wherein the through-bolt core is used to form the through bolt holes of the cylinder block, characterized in that: during the molding process, a through-bolt core is fixedly placed at the outer mold position outside the main cavity of the cylinder block, pressed onto the through-bolt core, and fixed in a predetermined position by the action of a vertical inclined surface to prevent movement.

[0006] Furthermore, the top of the through-hole screw core is provided with a connecting boss, which is narrower at the top and wider at the bottom, and has a vertically inclined outer surface on its side. The front end of the through-hole screw fixing core is provided with a connecting groove, which is narrower at the top and wider at the bottom and corresponds to the connecting boss of the through-hole screw core, and has a vertically inclined inner surface on its side. The connecting boss of the through-hole screw core is embedded in the connecting groove of the through-hole screw fixing core, and the inner inclined surface of the connecting groove is closely fitted with the outer inclined surface of the connecting boss, so as to realize the pressing and positioning of the through-hole screw core by the through-hole screw fixing core, thereby completing the fixing of the through-hole screw core.

[0007] Furthermore, the connecting boss is a frustum, the connecting groove is a frustum groove, and the outer and inner inclined surfaces are planes.

[0008] Furthermore, the connecting boss is a frustum of a cone, the connecting groove is a conical groove, and the outer and inner inclined surfaces are conical surfaces.

[0009] Furthermore, the method for fixing the through-hole mud core includes the following specific steps: 1) Use a core box to create through screw holes to fix the mud core; 2) During the cylinder block molding process, positions and cavities are reserved on the outer mold position outside the main cavity and on the cover box to accommodate the core with through screw holes and the core with through screw holes for fixing. 3) After the cylinder block molding wooden mold is released, the through screw hole core is first dropped into the predetermined cavity, and then the through screw hole fixing core made in step 1) is placed on the outer mold position reserved in step 2) and pressed on the through screw hole core. The inner inclined surface of the connecting groove of the through screw hole fixing core is tightly attached to the outer inclined surface of the connecting boss of the through screw hole core, thereby realizing the positioning and fixing of the through screw hole fixing core on the through screw hole core. 4) Lower the lid to complete the box packing process.

[0010] Furthermore, in step 2), a gap is left between the cavity reserved on the cover box and the core fixed by the through screw hole to accommodate the offset of the cover box when the box is assembled.

[0011] Compared with the prior art, the present invention has achieved the following beneficial effects: This invention uses a combined core instead of the traditional metal positioning plate or core support to fix the core through the screw hole. By using the fit of the inclined surfaces, the core fixing core through the screw hole is firmly combined with the core through the screw hole, ensuring reliable fixation of the core through the screw hole during the casting and pouring process. This avoids the formation of metal inclusion defects in the casting, reduces the risk of product scrap, reduces rework time, improves product quality stability, and reduces production costs. Attached Figure Description

[0012] Figure 1 This is a cross-sectional view of the cylinder block.

[0013] Figure 2 This is a schematic diagram of an existing method for fixing a core with a through-hole screw.

[0014] Figure 3 This is a schematic diagram of a core through a screw hole.

[0015] Figure 4 A schematic diagram of fixing the mud core using a through-hole screw.

[0016] Figure 5 A schematic diagram showing the connection and fixation of the core to the through-hole screw hole.

[0017] Figure 6 The diagram shows the state of the core material after it has been placed and the core material for fixing the core material through the screw hole.

[0018] Figure 7 This is a flowchart of the method of the present invention.

[0019] In the picture, 1—Cylinder body, 2—Through bolt hole, 3—Through bolt hole core, 31—Connecting boss, 32—Outer bevel, 4—Through bolt hole fixing core, 41—Connecting groove, 42—Inner bevel, 5—Metal positioning plate. Detailed Implementation

[0020] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but this should not be construed as limiting the scope of protection claimed by the present invention.

[0021] This invention is used to fix the core of the through-hole screw during the cylinder block molding process. Please refer to [link / reference]. Figure 1 The cylinder body 1 is provided with a plurality of through bolt holes 2, and the through bolt hole core is used to shape the through bolt holes 2 of the cylinder body 1.

[0022] Example Please see Figure 7 The method for fixing the through-hole mud core during the cylinder block shaping process of the present invention includes the following steps: 1) Use a core box to make through screw holes to fix the mud core.

[0023] To secure the through-hole core, this invention considers using a combined core; during cylinder block design, the through-hole core is fixed to secure the through-hole core, and the inclined surface design prevents the through-hole core from escaping.

[0024] Please see Figure 3First, a connecting boss 31 is made on the top of the threaded core 3. The connecting boss 31 is narrow at the top and wide at the bottom, and has a vertical outer bevel 32 on the side.

[0025] Then, use the core box to create through-hole screw holes to fix the mud core 4. Please refer to [link / reference]. Figure 4 The front end of the through-hole fixed mud core 4 is provided with a connecting groove 41. The shape of the connecting groove 41 is narrow at the top and wide at the bottom and corresponds to the connecting boss 31 of the through-hole mud core 3. The side is provided with a vertical inner inclined surface 42.

[0026] The connecting boss 31 of the through-hole screw core 3 can be a frustum, the connecting groove 41 of the through-hole screw core 4 is a frustum groove, and the outer inclined surface 32 and the inner inclined surface 42 are planes.

[0027] Alternatively, the connecting boss 31 of the through-hole screw core 3 can also be a truncated cone, the connecting groove 41 of the through-hole screw core fixing 4 can be a conical groove, and the outer inclined surface 32 and the inner inclined surface 42 can be conical surfaces.

[0028] 2) During the cylinder block molding process, positions and cavities are reserved on the outer mold position outside the main cavity and on the cover box to accommodate the core with through screw holes and the core with through screw holes for fixing.

[0029] During cylinder block molding, the main cavity of the cylinder block shape is created using a wooden mold and resin sand, simultaneously forming the outer mold. A fixing position is reserved at the outer mold location for the through-hole screw core 3 and the through-hole fixing core 4; a cavity is also reserved on the cover box to accommodate the through-hole fixing core 4. Considering the potential risk of cover box misalignment during assembly, the reserved cavity on the cover box is enlarged, leaving sufficient clearance between it and the through-hole fixing core 4 to increase the allowable error tolerance during production.

[0030] 3) Use the through screw hole fixing core to position and fix the through screw hole core.

[0031] After the cylinder block molding is completed, the through-screw hole core 3 is first placed into the predetermined cavity. Then, the through-screw hole fixing core 4, made in step 1), is placed in the outer mold position reserved in step 2) and pressed onto the through-screw hole core 3. The connecting boss 31 of the through-screw hole core 3 is then embedded into the connecting groove 41 of the through-screw hole fixing core 4. Figure 5 This ensures that the inner inclined surface 42 of the connecting groove 41 closely fits the outer inclined surface 32 of the connecting boss 31, firmly uniting the two mud cores. Please refer to [link / reference]. Figure 6 This enables the through-hole fixing core 4 to position and fix the through-hole fixing core 3.

[0032] 4) Finally, lower the lid to complete the box packing process.

[0033] The scope of protection claimed by this invention is not limited to the above embodiments, but should also include other variations and alternatives that are obvious to this invention.

Claims

1. A method for fixing a through-bolt core during cylinder block molding, the through-bolt core being used to form the through bolt holes of the cylinder block, characterized in that: During the molding process, a through-hole fixing core is fixedly placed at the outer mold position on the outside of the main cavity of the cylinder block, and pressed on the through-hole fixing core. The through-hole fixing core is fixed in the predetermined position by the action of the vertical inclined plane to prevent movement.

2. The method for fixing the through-hole mud core during cylinder block molding according to claim 1, characterized in that: The top of the through-hole screw core is provided with a connecting boss, which is narrower at the top and wider at the bottom, and has a vertically inclined outer surface on its side. The front end of the through-hole screw fixing core is provided with a connecting groove, which is narrower at the top and wider at the bottom and corresponds to the connecting boss of the through-hole screw core, and has a vertically inclined inner surface on its side. The connecting boss of the through-hole screw core is embedded in the connecting groove of the through-hole screw fixing core, and the inner inclined surface of the connecting groove is in close contact with the outer inclined surface of the connecting boss, so as to realize the pressing and positioning of the through-hole screw core by the through-hole screw fixing core, thereby completing the fixing of the through-hole screw core.

3. The method for fixing the through-hole mud core during cylinder block molding according to claim 2, characterized in that: The connecting boss is a frustum, the connecting groove is a frustum groove, and the outer and inner inclined surfaces are planes.

4. The method for fixing the through-hole mud core during cylinder block molding according to claim 2, characterized in that: The connecting boss is a truncated cone, the connecting groove is a conical groove, and the outer and inner inclined surfaces are conical surfaces.

5. The method for fixing the through-hole mud core during cylinder block molding according to claim 2, characterized in that: The method for fixing the through-hole mud core includes the following specific steps: 1) Use a core box to create through screw holes to fix the mud core; 2) During the cylinder block molding process, positions and cavities are reserved on the outer mold position outside the main cavity and on the cover box to accommodate the core with through-hole screw holes and the core with through-hole screw hole fixing. 3) After the cylinder block molding wooden mold is released, the through screw hole core is first dropped into the predetermined cavity, and then the through screw hole fixing core made in step 1) is placed on the outer mold position reserved in step 2) and pressed on the through screw hole core. The inner inclined surface of the connecting groove of the through screw hole fixing core is tightly attached to the outer inclined surface of the connecting boss of the through screw hole core, thereby realizing the positioning and fixing of the through screw hole fixing core on the through screw hole core. 4) Lower the lid to complete the box packing process.

6. The method for fixing the through-hole mud core during cylinder block molding according to claim 5, characterized in that: In step 2), a gap is left between the cavity reserved on the cover box and the core fixed by the through screw hole to allow for the offset of the cover box when the box is assembled.

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