An integrated high-combustion-chamber four-cylinder cast-iron racing engine cylinder block

Abstract

This invention relates to the field of internal combustion engine manufacturing technology, specifically a one-piece, heightened combustion chamber four-cylinder cast iron racing engine block. It includes a cylinder block base with four cylinder bores, a crankshaft mounting cavity, lubrication oil passages, and optimized cooling water passages. A cylinder head mounting surface is located at the upper end of the cylinder block base. An integrated heightened structure is continuously arranged circumferentially along the four cylinder bores and integrally cast with the cylinder block base using the same cast iron material. Optimized cooling water passages surround each cylinder bore. The integrated heightened structure and the cylinder block base are connected by a continuous solid structure to form an integral load-bearing frame. The one-piece heightened structure and cylinder block base are integrally cast using the same cast iron material, and the cylinder head mounting surface is directly formed on the heightened structure, eliminating the problems of thermal expansion mismatch and sealing failure caused by material differences in external gaskets. The continuous heightened structure along the circumferential direction of the cylinder bores improves the structural strength and deformation resistance of the upper end of the cylinder block.

Description

Technical Field

[0001] This invention relates to the field of internal combustion engine manufacturing technology, and in particular to an integrated, heightened combustion chamber, four-cylinder cast iron racing engine block. Background Technology

[0002] The cylinder block of a four-cylinder cast iron engine is the main support structure of the engine, cast in one piece from gray cast iron or alloy cast iron. As the core skeleton of the entire engine, it houses moving parts such as pistons and crankshafts. Together with the pistons and cylinder head, it forms the combustion chamber to withstand the high-pressure impact of combustion. Simultaneously, it relies on internal water and oil circuits for engine cooling and pressure lubrication. Cast iron itself is rigid, wear-resistant, deformation-resistant, and has excellent vibration damping and noise reduction properties. The manufacturing process is mature and the cost is low. It is widely used in heavy-duty four-cylinder diesel engines, construction machinery, and older high-torque power models.

[0003] In the field of racing modifications, to change the combustion chamber volume, lower the compression ratio, and adapt to high-octane racing fuel, the industry-standard modification method is to add a steel gasket to the cylinder head mating surface to raise the chamber and increase its volume. This split-layer structure has inherent structural defects: First, the steel gasket and the cast iron cylinder block are made of different materials, resulting in a significant difference in their coefficients of thermal expansion. Under high-temperature conditions, their deformation is inconsistent, and gaps are easily generated at the mating surface, leading to a very high probability of seal failure. Second, the split structure disrupts the overall load-bearing frame of the upper part of the cylinder block, significantly reducing its resistance to vibration and impact, and making it prone to misalignment and deformation under the harsh conditions of racing. Third, this modification method lacks a standardized processing procedure, resulting in poor consistency in the height of the four cylinders, large deviations in the compression ratio of each cylinder, and noticeable engine vibration during operation. Summary of the Invention

[0004] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0005] In view of the problems that exist in the above-mentioned or existing four-cylinder cast iron racing engine blocks, which use external steel pads to elevate the cylinder block, resulting in sealing failure due to the mismatch of thermal expansion between different materials and damage to the upper load-bearing frame of the split structure, this invention is proposed.

[0006] Therefore, the object of the present invention is to provide an integrated, heightened combustion chamber four-cylinder cast iron racing engine block.

[0007] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a cylinder block base, wherein the cylinder block base is provided with four cylinder bores, a crankshaft mounting cavity, a lubricating oil passage, and a cooling optimization water passage; the upper end of the cylinder block base is provided with a cylinder head mounting mating surface; the cylinder head mounting mating surface is formed on an integral raised structure on the upper part of the cylinder block base; the integral raised structure is continuously arranged along the circumference of the four cylinder bores and is integrally cast with the cylinder block base using the same cast iron material; the cooling optimization water passage is arranged around each of the cylinder bores; the integral raised structure and the cylinder block base are connected by a continuous solid structure to form an integral load-bearing frame.

[0008] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention, wherein: the integrated heightened structure is integrally heightened along the axial direction of the cylinder bore to increase the axial dimension between the cylinder head mounting surface and the cylinder block base.

[0009] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention, the height of the integrated heightened structure is 10mm.

[0010] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention, wherein: the optimized cooling water channels are continuously arranged around the four cylinder bores to form a surrounding cooling structure.

[0011] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention, wherein: the cooling optimization channel forms an upper cooling extension section in the area near the cylinder head mounting joint surface, the upper cooling extension section is correspondingly provided with the integrated heightened structure, and the extension height of the upper cooling extension section along the cylinder bore axial direction is consistent with the heightened height of the integrated heightened structure, so that the coolant flow area extends to the upper region of the combustion chamber corresponding to the integrated heightened structure.

[0012] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention, wherein the heightened areas of the integrated heightened structure corresponding to the four cylinder bores are set at the same height.

[0013] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine cylinder block of the present invention, wherein: the cylinder block base and the integrated heightened structure are integrally cast from the same cast iron material.

[0014] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine cylinder block of the present invention, wherein: the cylinder block base and the integrated heightened structure are integrally cast from molten iron that has undergone segmented constant temperature melting and inoculation treatment.

[0015] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine cylinder block of the present invention, wherein the cylinder block base and the integrated heightened structure are integrally formed by directional flow controlled casting process.

[0016] As a preferred embodiment of the integrated heightened combustion chamber four-cylinder cast iron racing engine cylinder block of the present invention, wherein: the cylinder block base and the integrated heightened structure are treated with a gradient constant temperature stress relief aging process.

[0017] The integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention has the following advantages: The integrated heightened structure and the cylinder block base are integrally cast from the same cast iron material, and the cylinder head mounting surface is directly formed on the heightened structure, eliminating the problems of thermal expansion mismatch and sealing failure caused by material differences in external gaskets; The heightened structure is continuously arranged along the circumference of the cylinder bore and connected to the cylinder block base through a continuous solid structure to form an integral load-bearing frame, improving the structural strength and deformation resistance of the upper part of the cylinder block. The optimized cooling water channel forms an upper cooling extension section near the cylinder head mounting surface, corresponding to the integrated heightened structure, allowing the coolant flow area to extend to the upper part of the heightened combustion chamber, thereby improving the cooling coverage near the integrated heightened structure and reducing local heat accumulation during high-load operation. Attached Figure Description

[0018] To more clearly illustrate the technical solutions of the 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. Wherein: Figure 1 This is a front view of the external structure of the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention.

[0019] Figure 2 This is a schematic diagram of the internal structure of the "HH" longitudinal stepped section in the main view of the present invention. Detailed Implementation

[0020] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0021] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0022] Secondly, the term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in an embodiment of this application" appearing in different places in this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments.

[0023] Example 1 Reference Figures 1-2 This is the first embodiment of the present invention, which provides an integrated heightened combustion chamber four-cylinder cast iron racing engine block.

[0024] like Figure 1 and Figure 2 As shown, this embodiment provides an integrated heightened combustion chamber four-cylinder cast iron racing engine block. This block is mainly used in four-cylinder racing engines, and is especially suitable for racing modification scenarios that require adjusting the effective volume of the combustion chamber, reducing the compression ratio, and improving the heat resistance and durability of the block based on the original engine structure.

[0025] In the embodiments of this application, the engine block includes a cylinder block base 1, which is an integrally cast iron cylinder block. The cylinder block base 1 has four cylinder bores 11, a crankshaft mounting cavity 12, a lubricating oil passage 13, and a cooling optimization water passage 14. The four cylinder bores 11 are arranged sequentially along the length of the cylinder block base 1 to accommodate piston assemblies and form four cylinder working spaces. The crankshaft mounting cavity 12 is located at the lower part of the cylinder block base 1 and is used to mount the engine crankshaft and related support components. The lubricating oil passage 13 is disposed inside the cylinder block base 1 to provide lubricating oil to the crankshaft, piston, connecting rod, and related friction pairs. The cooling optimization water passage 14 is disposed inside the cylinder block base 1 to allow coolant circulation, thereby removing heat transferred to the cylinder block base 1 during engine combustion.

[0026] like Figure 1 As shown, the upper end of the cylinder block base 1 is provided with a cylinder head mounting mating surface 2, which is used to connect and mate with the engine cylinder head. The cylinder block base 1 is also provided with mounting and fixing holes 15, which are used to mate with the engine cylinder head, fasteners, or related assembly components to achieve a reliable connection between the cylinder block and the cylinder head. The outer wall of the cylinder block base 1 is provided with an outer wall water channel reserved position 16, which corresponds to the position of the external connection structure or corresponding cooling channel of the engine cooling system, so that coolant can enter or flow through the internal cooling area of ​​the cylinder block.

[0027] like Figure 2 As shown, a reference datum plane 17 is provided on the cylinder block base 1. The reference datum plane 17 is located at the lower part of the cylinder block base 1 and is used as a reference datum during cylinder block machining or assembly. The inner wall 18 of the cylinder bore extends axially along the cylinder bore 11 to the cylinder head mounting mating surface 2.

[0028] In the embodiments of this application, the integrated heightening structure 3 is disposed in the upper region of the cylinder block base 1 and is continuously disposed along the four cylinder bores 11 in the circumferential direction. The integrated heightening structure 3 is disposed to raise the cylinder bore axis 11 as a whole, so as to increase the axial dimension between the cylinder head mounting surface 2 and the cylinder block base 1.

[0029] In a preferred embodiment of this application, the height of the integrated heightening structure 3 is 10mm. This integrated heightening structure 3 increases the axial dimension between the cylinder head mounting surface 2 and the cylinder block base 1, thereby increasing the effective volume of the engine combustion chamber and meeting the requirements of racing engines for compression ratio adjustment and power output tuning.

[0030] In current racing modification methods, a 10mm thick steel gasket is typically installed between the original cylinder block and cylinder head to increase combustion chamber volume. This method is a post-installation modification structure, where the steel gasket and the cast iron cylinder block have a non-material interface. When the engine is under high temperature, high pressure, and high frequency vibration conditions, the thermal expansion and deformation of the steel gasket and the cast iron cylinder block are inconsistent, which can easily lead to tiny gaps at the interface, resulting in problems such as blow-by, oil leaks, water leaks, or blown head gaskets.

[0031] Unlike the aforementioned split-type cylinder headstock structure, this integrated lifting structure 3 is directly part of the cylinder block body. The integrated lifting structure 3 and the cylinder block base 1 are integrally cast from the same cast iron material, eliminating the need for steel plate / gasket connection interfaces, welded connection interfaces, and mechanical assembly connection interfaces. Therefore, during high-temperature engine operation, there will be no interface misalignment issues between the integrated lifting structure 3 and the cylinder block base 1 due to differences in thermal expansion between dissimilar materials.

[0032] In the embodiments of this application, the integrated heightening structure 3 is continuously arranged circumferentially along the four cylinder bores 11, and the heightening areas corresponding to the four cylinder bores 11 are set at the same height. Since the integrated heightening structure 3 is formed integrally during the casting stage, the heightening height corresponding to each cylinder can be kept consistent, thereby avoiding the problem of inconsistent cylinder heights caused by machining errors, assembly errors, or seal compression differences in traditional steel plate heightening methods. After the heightening areas corresponding to the four cylinder bores 11 are set at the same height, the structural dimensions corresponding to the four combustion chambers can be more consistent, which is beneficial to improving the power output balance of the four cylinders and reducing the risk of engine vibration at high speeds.

[0033] In the embodiments of this application, the integrated heightening structure 3 and the cylinder block base 1 are connected by a continuous solid structure. Specifically, the lower part of the integrated heightening structure 3 and the upper part of the cylinder block base 1 are continuously connected, without any layering, splicing, or assembly gaps between them. During engine operation, periodic high-temperature and high-pressure gas loads are generated in the combustion chamber. These loads are transferred to the integrated heightening structure 3 through the cylinder head mounting surface 2, and then from the integrated heightening structure 3 to the cylinder block base 1. Since the integrated heightening structure 3 and the cylinder block base 1 are integrally cast from the same cast iron material, the load transfer path is continuous, which can reduce the risk of stress concentration, seal attenuation, or assembly misalignment at the joint surface in traditional split heightening structures.

[0034] like Figure 2 As shown, the cooling optimization channel 14 in this embodiment is a widened and expanded channel. The cooling optimization channel 14 is disposed inside the cylinder block base 1 and is continuously arranged around the four cylinder bores 11 to form a cooling structure surrounding the combustion chamber area, used to cool the high heat load area around the four cylinder bores 11.

[0035] In the embodiments of this application, the widened area of ​​the cooling optimization channel 14 is provided around all four cylinder bores 11, and not just on one side or in a local area of ​​a single cylinder bore. Coolant flow areas are formed around the outer periphery of the cylinder bores 11 corresponding to the first, second, third, and fourth cylinders, so that the coolant can circulate around the area surrounding the four cylinder bores 11, thereby evenly removing the heat generated when the four cylinders work simultaneously.

[0036] In a preferred embodiment of this application, a cylinder bore wall portion is formed between the inner wall 18 of the cylinder bore and the optimized cooling channel 14. The cylinder bore wall portion is used to transfer heat from the periphery of the combustion chamber to the coolant in the optimized cooling channel 14 while ensuring the structural strength of the cylinder bore 11. Specifically, the total wall thickness of the cylinder bore wall portion corresponding to the opposite sides around the four cylinder bores 11 is approximately 20 mm, and the radial wall thickness on one side is approximately 10 mm. At the same time, the internal channel wall of the optimized cooling channel 14 is thinned by approximately 2 mm compared to the corresponding channel wall before expansion, so that the coolant flow area can be arranged close to the high heat load area around the four cylinder bores 11, and the flow space of the coolant inside the cylinder block base 1 is increased.

[0037] In the embodiments of this application, the coolant circulation path is as follows: the coolant is driven by the engine water pump into the inlet of the cylinder block base 1, then flows through the oil cooling chamber, and enters the cooling area corresponding to the fourth cylinder through the circulation hole; the coolant then flows sequentially through the cooling optimization channels 14 around the four cylinder bores 11, passing through the cooling areas corresponding to the third, second, and first cylinders; after passing through the area around the four cylinder bores 11, the coolant flows to the cylinder head through the upward channel outlet, and returns to the radiator through the cylinder head outlet. Through the above circulation path, the coolant can sequentially pass through the high heat load area around the four cylinder bores 11, so that the working heat of the four cylinders can be continuously removed.

[0038] In the embodiments of this application, a connected cooling area is formed between two adjacent cylinder bores 11 through a cooling optimization channel 14, allowing the coolant to flow continuously between adjacent cylinder bores 11 and reducing heat concentration caused by insufficient coolant flow between adjacent cylinder bores 11. The cooling optimization channel 14 forms a continuous, surrounding cooling path around the four cylinder bores 11, allowing the coolant to flow sequentially from the corresponding area of ​​the fourth cylinder to the corresponding areas of the third, second, and first cylinders, avoiding uneven heat dissipation among the cylinders caused by the coolant only passing through a local cylinder bore area.

[0039] In a preferred embodiment of this application, to reduce the flow resistance of the coolant within the optimized cooling channel 14, the inner wall of the optimized cooling channel 14 adopts a rounded transition structure. Specifically, a sand core structure corresponding to the optimized cooling channel 14 is formed using 3D sand printing to reduce protrusions, depressions, or irregular transition positions formed during sand removal in traditional metal mold casting. The inner wall of the channel formed by 3D sand printing can form a continuous rounded transition surface, reducing sharp bends, local necking, and stagnation points in the water flow, making the coolant flow more smoothly within the optimized cooling channel 14.

[0040] In the embodiments of this application, the cooling optimization channel 14 forms an upper cooling extension section 141 in the area near the cylinder head mounting joint surface 2. The upper cooling extension section 141 is correspondingly provided with the integrated heightening structure, and the extension height of the upper cooling extension section 141 along the cylinder bore 11 axis is consistent with the heightening height of the integrated heightening structure, so that the coolant flow area extends to the upper area of ​​the combustion chamber corresponding to the integrated heightening structure 3.

[0041] In a preferred embodiment of this application, the height of the integrated heightening structure 3 is 10mm, and the extension height of the upper cooling extension section 141 along the cylinder bore 11 axial direction is also 10mm. That is, while the integrated heightening structure 3 increases the height of the cylinder head mounting surface 2 relative to the cylinder block base 1 by 10mm along the cylinder bore 11 axial direction, the cooling optimization channel 14 simultaneously forms a 10mm upper cooling extension section 141 in the area near the cylinder head mounting surface 2, so that the coolant flow area can correspond to the upper area of ​​the heightened combustion chamber.

[0042] When the engine is operating at high speed and high load, the combustion chamber continuously generates a large amount of heat. This heat is transferred outward through the cylinder bore inner wall 18, the integrated heightened structure 3, and its surrounding cast iron structure. As the coolant circulates within the optimized cooling channel 14, it removes heat from around each cylinder through the widened expansion area surrounding the four cylinder bores 11. Simultaneously, it cools the upper region of the combustion chamber corresponding to the integrated heightened structure 3 through the upper cooling extension section 141. This reduces the operating temperature of the upper region of the cylinder block base 1, decreases heat accumulation, suppresses high-temperature power attenuation, and improves the thermal stability and durability of the engine during continuous operation.

[0043] In the embodiments of this application, the lubricating oil passage 13 is located inside the cylinder block base 1 and corresponds to the internal lubrication system of the cylinder block base 1. When the engine is running, lubricating oil is delivered to the crankshaft, connecting rod, piston and related friction pairs through the lubricating oil passage 13 to reduce friction and wear between moving parts.

[0044] It should be noted that the lubricating oil passage 13 and the cooling optimization water passage 14 are respectively located in different functional areas inside the cylinder block base 1, and are used for lubrication and cooling respectively.

[0045] In this embodiment, the cylinder base 1 and the integrated heightened structure 3 are integrally cast from molten iron that has undergone segmented isothermal melting (refining) and inoculation treatment. Specifically, during manufacturing, the cast iron raw material is first melted to obtain molten iron for casting the cylinder. During the melting process, the molten iron undergoes segmented isothermal refining treatment. By controlling the temperature of the molten iron in stages, it is kept in a state suitable for impurity removal and microstructure control.

[0046] In a preferred embodiment of this application, during the segmented isothermal refining process, the molten iron undergoes slag removal, desulfurization, and deoxidation treatments to reduce the impact of inclusions, sulfur and oxygen impurities, and gas defects on the casting microstructure and improve the purity of the molten iron. After the segmented isothermal refining is completed, the molten iron undergoes an inoculation treatment. The inoculation treatment is achieved by adding an inoculant to the molten iron to improve the microstructure of the cast iron, making the graphite morphology and matrix structure more uniform. Through the inoculation treatment, the metallographic structure of the area around the combustion chamber, the inner wall 18 of the cylinder bore, and the area where the integrated heightened structure 3 is located tends to be dense and uniform, thereby improving the wear resistance, fatigue resistance, and structural stability of the cylinder block.

[0047] Furthermore, the molten iron, after being refined and inoculated in stages at a constant temperature, is injected into a pre-set mold cavity for casting. In this embodiment, the cylinder base 1 and the integrated heightened structure 3 are integrally formed using a directional controlled flow casting process. During the directional controlled flow casting process, by arranging the gating system, overflow port, and filling path, the molten iron enters the mold cavity in a predetermined direction, and gradually completes the filling of the cylinder base 1, the integrated heightened structure 3, the area surrounding the cylinder bore 11, the area surrounding the cooling optimized water channel 14, the area surrounding the lubricating oil channel 13, and other structural areas.

[0048] Directional controlled-flow casting technology can control the flow rate and filling pressure of molten iron, reducing the risks of shrinkage cavities, porosity, gas porosity, and localized stress concentration that are easily generated during ordinary free casting. In particular, the 10mm thickened structural area is located at the upper end of the cylinder base 1, which is a region of increased thickness. Improper casting control can easily lead to uneven solidification or a loose microstructure in this area. Directional controlled-flow casting allows the molten iron to form a continuous casting structure between the 10mm thickened structural area and the cylinder base 1, improving the overall integrity of the 10mm thickened structure and the cylinder base 1.

[0049] In a preferred embodiment of this application, after the casting is completed and formed, the cylinder base 1 and the integrated heightened structure 3 undergo gradient isothermal stress-relieving aging treatment. Specifically, the cast cylinder is placed in a heat treatment device and heated, held, and cooled according to preset temperature stages to gradually release the residual stress inside the casting. Compared with natural aging, gradient isothermal stress-relieving aging treatment can more fully balance the stress distribution inside the cylinder, reducing the risk of end face warping, dimensional drift, or local deformation caused by residual stress release during subsequent machining and actual use.

[0050] In a preferred embodiment of this application, after the aforementioned gradient isothermal stress-relieving aging treatment, the cylinder block also needs to be machined. Machining includes processing the cylinder bore 11, the inner wall 18 of the cylinder bore, the crankshaft mounting cavity 12, the mounting fixing hole 15, the cylinder head mounting mating surface 2, and related external mounting references. The cylinder head mounting mating surface 2, as the sealing mating surface between the cylinder block and the cylinder head, directly affects the engine's airtightness, oil-water sealing performance, and long-term operational reliability through its machining accuracy.

[0051] Specifically, for the cylinder head mounting mating surface 2, a composite machining method combining rough machining, low-temperature aging, semi-finishing, and precision grinding can be adopted. First, the cylinder head mounting mating surface 2 is rough machined to remove casting allowance and form a preliminary flat surface; then, low-temperature aging treatment is performed to release the machining stress generated during rough machining; next, the cylinder head mounting mating surface 2 is semi-finished to correct the flat shape and dimensions; finally, precision grinding is performed to give the cylinder head mounting mating surface 2 a high degree of flatness and parallelism.

[0052] The aforementioned composite processing method reduces residual stress concentration caused by single processing, improving the dimensional stability of the cylinder head mounting surface 2 during long-term use. When the engine is subjected to high temperature, high pressure, and strong vibration for extended periods under racing conditions, the cylinder head mounting surface 2 is less prone to warping due to stress release or thermal deformation, thereby improving the sealing performance between the cylinder head and the cylinder block.

[0053] In the embodiments of this application, when the engine block is assembled, the cylinder head is installed on the cylinder head mounting mating surface 2, the piston assembly is installed in the four cylinder bores 11 respectively, the crankshaft is installed in the crankshaft mounting cavity 12, the lubricating oil is delivered to the corresponding lubrication position through the lubricating oil passage 13, and the coolant enters or flows through the cooling optimization water passage 14 through the reserved position 16 on the outer wall water passage and circulates inside the cylinder block base 1.

[0054] When the engine is running, fuel burns in the combustion chamber to produce high-temperature, high-pressure gas. This gas drives the piston to reciprocate, and the piston, through the connecting rod, drives the crankshaft to rotate and output power. Because the cylinder head mounting surface 2 is formed on the integrated heightening structure 3, and the integrated heightening structure 3 is raised along the axial direction of the cylinder bore 11, the effective volume of the combustion chamber is increased, thereby adapting to the requirements of racing engines to reduce the compression ratio and match the high-load power tuning.

[0055] During high-temperature engine operation, both the integrated heightening structure 3 and the cylinder block base 1 are made of the same cast iron material and are integrally cast structures. Therefore, the problem of inconsistent thermal expansion between the steel plate and the cast iron cylinder block, which is common in traditional steel plate heightening structures, is avoided. When the cylinder head mounting surface 2 is subjected to force, the load can be continuously transferred to the cylinder block base 1 through the integrated heightening structure 3, reducing the risk of misalignment at the connection interface of split heightening structures.

[0056] Meanwhile, the coolant circulates within the optimized cooling channel 14, cooling the area around the four cylinder bores 11 and the combustion chamber. Because the optimized cooling channel 14 increases the coolant flow space and improves coolant flow capacity, it can more quickly remove the heat generated by the simultaneous operation of multiple cylinders, reducing heat buildup. Therefore, during continuous high-speed, high-load engine operation, it can improve cylinder block thermal stability and suppress power loss caused by high temperatures.

[0057] Compared with traditional original factory cylinder blocks, this embodiment changes the relevant spatial structure of the combustion chamber through an integrated heightening structure 3, improves the heat dissipation state when four cylinders work simultaneously through cooling optimization water channels 14, and improves the microstructure and dimensional stability of the casting through segmented constant temperature refining, inoculation treatment, directional flow control casting, gradient constant temperature stress relief aging and composite precision machining, thereby improving the overall durability of the cylinder block.

[0058] Compared to the external steel plate-supported cylinder block modification, this embodiment eliminates the dissimilar material bonding structure between the steel plate gasket and the cast iron cylinder block. The integrated heightening structure 3 and the cylinder block base 1 are integrally cast, which reduces the number of assembly interfaces, lowers the risk of seal failure under high temperature and high pressure conditions, and improves reliability during continuous use in races.

[0059] It should be noted that, provided that the effective volume of the combustion chamber, the cylinder head installation relationship, and the overall engine assembly relationship are satisfied, the specific height of the integrated heightening structure 3 can be adaptively adjusted according to different engine models, racing tuning targets, compression ratio requirements, and structural strength requirements.

[0060] In summary, this embodiment achieves a comprehensive improvement in the performance of the racing engine cylinder block in terms of combustion chamber volume adjustment, sealing reliability, structural load-bearing capacity, heat dissipation capacity, thermal deformation resistance, and long-term durability by setting an integral heightening structure 3 on the upper part of the cylinder block base 1, which is integrally cast from the same cast iron material as the cylinder block base 1. The cylinder head mounting mating surface 2 is formed on the integral heightening structure 3. In conjunction with structures such as lubrication oil passage 13 and cooling water passage 14, the performance of the racing engine cylinder block is comprehensively improved in terms of combustion chamber volume adjustment, sealing reliability, structural load-bearing capacity, heat dissipation capacity, thermal deformation resistance, and long-term durability.

[0061] Example 2 Reference Figures 1-2 This is the second embodiment of the present invention. Unlike the previous embodiment, this embodiment provides a comparative experiment between the integrated heightened combustion chamber four-cylinder cast iron racing engine block and the original traditional four-cylinder cast iron block.

[0062] In the embodiments of this application, a factory-installed conventional four-cylinder cast iron cylinder block is selected as a comparative example, and the one-piece heightened combustion chamber four-cylinder cast iron racing engine cylinder block of Embodiment 1 is selected as an experimental example.

[0063] The comparison example is a stock four-cylinder cast iron cylinder block with a long service life. Its combustion chamber upper surface lacks an integrated heightening structure, and the cooling water channels have not been widened or optimized. Furthermore, the cylinder block manufacturing process employs conventional smelting, ordinary casting, natural aging, and conventional machining techniques. In racing modifications, if the combustion chamber volume needs to be adjusted to match power tuning, a 10mm thick steel shim plate must be installed between the stock cylinder block and cylinder head. This shim plate and the cylinder block base are separate assembly structures, representing a post-modification assembly method, resulting in dissimilar material interfaces and assembly connection points.

[0064] The experimental example is the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention, which includes a cylinder block base 1. The cylinder block base 1 has four cylinder bores 11, a crankshaft mounting cavity 12, an internal lubrication oil passage 13, and a cooling optimization water passage 14. The upper end of the cylinder block base 1 has a cylinder head mounting mating surface 2. The cylinder block base 1 has an inner wall of the cylinder bores. The integrated heightened structure 3 is located in the corresponding area at the upper end of the inner wall of the cylinder bores, and the cylinder head mounting mating surface 2 is heightened by 10mm along the cylinder bore axial direction relative to the position of the corresponding cylinder head mounting mating surface of the original model. The integrated heightened structure 3 and the cylinder block base 1 are integrally cast from the same cast iron material. The cooling optimization water passage 14 is a widened optimization water passage used to improve the flow capacity of coolant in the surrounding area of ​​the combustion chamber. Specifically, in the experimental example, the cooling optimization channel 14 is arranged around all four cylinder bores 11. The total wall thickness of the cylinder bore walls on both sides around the four cylinder bores 11 is about 20 mm, the radial wall thickness on one side is about 10 mm, and the internal channel wall of the cooling optimization channel 14 is thinned by about 2 mm.

[0065] According to actual installation tests, the coolant used in the comparative cylinder block installation was about 4L, and the coolant used in the experimental cylinder block installation was about 4.8L, thereby increasing the coolant flow space inside the cylinder block base 1.

[0066] In structural durability fatigue testing, the comparative and experimental examples were installed under the same test conditions for ultimate alternating load testing. During the test, the cylinder block was repeatedly subjected to alternating mechanical loads simulating racing conditions to detect the deformation of the cylinder block end face and the wear of the cylinder bore inner wall.

[0067] Test results show that, in the comparative example, after 180 hours of extreme alternating load testing, the cylinder end face showed slight deformation and the wear on the inner wall of the cylinder bore was 0.12 mm; in the experimental example, after 500 hours of testing under the same load conditions, the cylinder end face deformation was less than 0.02 mm and the wear on the inner wall of the cylinder bore was 0.03 mm.

[0068] The results above show that, compared to the original factory-made four-cylinder cast iron cylinder block, the cylinder block of this invention maintains smaller end face deformation and lower cylinder bore inner wall wear even under longer testing periods. This is because the integrated 10mm raised structure area of ​​the cylinder block is integrally cast with the cylinder block base 1. The integrated 10mm raised structure area extends integrally from the upper part of the cylinder block base 1, eliminating the need for separate raised parts and assembly interfaces, thus creating a continuous stress-bearing structure in the upper part of the cylinder block. Furthermore, the segmented isothermal refining, inoculation treatment, and directional flow-controlled casting processes improve the microstructure density of the cylinder block base 1 and the integrated raised structure, enhancing the cylinder block's fatigue resistance and wear resistance under alternating loads.

[0069] In the high-temperature deformation resistance test, the comparative example and the experimental example were placed in a constant temperature test environment of 380℃ for continuous heat preservation, and the thermal deformation displacement of the cylinder block under high temperature conditions was measured. The test results show that the thermal deformation displacement of the comparative example under this high-temperature condition is 0.08mm; the overall deformation of the experimental example under the same high-temperature condition is 0.02mm.

[0070] The results above show that the cylinder block of the present invention has better high-temperature dimensional stability compared to the original traditional four-cylinder cast iron cylinder block. This is because the cylinder block base 1 and the integrated heightened structure of the present invention are integrally cast from the same cast iron material and undergo gradient isothermal stress-relief aging treatment, which can gradually release residual casting stress and reduce the risk of natural deformation and end-face warping during subsequent high-temperature use.

[0071] In the heat dissipation performance test, the comparative example and the experimental example were installed on the same engine test platform, and the average operating temperature of the cylinder block was measured under full load and rated speed conditions. The test results showed that the average operating temperature of the comparative example was 126℃, and the average operating temperature of the experimental example was 108℃.

[0072] As can be seen from the above results, the cylinder block of the present invention can effectively reduce the operating temperature of the cylinder block during full-load operation. This is because the cylinder block of the present invention has a cooling optimization channel 14 inside the cylinder block base 1. The cooling optimization channel 14 is arranged around all four cylinder bores 11, allowing the coolant to flow closer to the high-heat-load areas around the four cylinder bores 11. The cooling optimization channel 14 forms an upper cooling extension section 141 corresponding to the integrated heightened structure in the area near the cylinder head mounting surface 2, allowing the coolant flow area to extend to the upper region of the combustion chamber corresponding to the integrated heightened structure. After entering through the inlet, the coolant passes through the oil cooling chamber and circulation holes into the corresponding region of the fourth cylinder, then flows sequentially through the corresponding regions of the third, second, and first cylinders, and flows back to the radiator through the upper water channel, thereby reducing heat accumulation during simultaneous operation of the four cylinders and suppressing high-temperature power attenuation.

[0073] Based on the above structural durability fatigue test, high temperature resistance deformation test, and heat dissipation performance test, it can be seen that the integrated heightened combustion chamber four-cylinder cast iron racing engine block of the present invention has improved structural durability, high temperature dimensional stability, and heat dissipation capacity compared with the original traditional four-cylinder cast iron block.

[0074] Specifically, this invention integrally forms a 10mm heightened structural area on the upper part of the cylinder bore inner wall, increasing the combustion chamber plane by 10mm relative to the reference plane, thereby adjusting the effective volume of the combustion chamber and avoiding the connection interface problems caused by traditional post-assembly structures. The invention also improves the coolant flow capacity around the combustion chamber and the corresponding area of ​​the heightened structure by using optimized cooling channels 14 surrounding all four cylinder bores 11, an upper cooling extension section 141 corresponding to the integral heightened structure, and a coolant circulation path flowing sequentially from the fourth cylinder to the first cylinder. Furthermore, the invention enhances the overall density and dimensional stability of the cylinder block through segmented isothermal refining, inoculation treatment, directional flow-controlled casting, and gradient isothermal stress-relieving aging treatment. Therefore, the cylinder block of this invention can better meet the requirements of high-speed, high-load, and long-term continuous operation conditions of racing engines.

[0075] It is important to note that the constructions and arrangements of this application shown in several different exemplary embodiments are merely illustrative. Although only a few embodiments are described in detail in this disclosure, those who consult this disclosure will readily understand that many modifications are possible (e.g., changes in the size, dimensions, structure, shape, and proportions of various elements, as well as parameter values ​​(e.g., temperature, pressure, etc.), mounting arrangements, use of materials, color, orientation, etc.) without substantially departing from the novel teachings and advantages of the subject matter described in this application). For example, an element shown as integrally formed may be composed of multiple parts or elements, the position of elements may be inverted or otherwise altered, and the nature or number or position of discrete elements may be changed or altered. Therefore, all such modifications are intended to be included within the scope of the invention. The order or sequence of any process or method steps may be changed or rearranged according to alternative embodiments. In the claims, any "device plus function" clause is intended to cover the structure described herein that performs the function, and not only structurally equivalent but also equivalent in structure. Other substitutions, modifications, alterations, and omissions may be made in the design, operation, and arrangement of the exemplary embodiments without departing from the scope of the invention. Therefore, the present invention is not limited to the specific embodiments, but extends to various modifications that still fall within the scope of the appended claims.

[0076] Furthermore, in order to provide a concise description of exemplary embodiments, not all features of actual embodiments (i.e., those features that are not relevant to the best mode of carrying out the invention as currently considered, or those features that are not relevant to implementing the invention) may be omitted.

[0077] It should be understood that numerous specific implementation decisions can be made during the development of any practical implementation, such as in any engineering or design project. Such development efforts may be complex and time-consuming, but for those skilled in the art who benefit from this disclosure, the development effort will be a routine work of design, manufacturing, and production without requiring much experimentation.

[0078] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the spirit and scope of the technical solutions of the present invention, and all such modifications or substitutions should be covered within the scope of the claims of the present invention.

Claims

1. A one-piece, heightened combustion chamber four-cylinder cast iron racing engine block, characterized in that, include: The cylinder block base has four cylinder bores, a crankshaft mounting cavity, a lubricating oil passage, and a cooling water passage. The upper end of the cylinder block base has a cylinder head mounting surface. The cylinder head mounting mating surface is formed on an integral heightening structure on the upper part of the cylinder block base. The integral heightening structure is continuously arranged along the circumference of the four cylinder holes and is integrally cast with the cylinder block base using the same cast iron material. The optimized cooling channels are arranged around each of the cylinder bores; The integrated heightened structure is connected to the cylinder block base through a continuous solid structure to form an overall load-bearing frame.

2. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The integrated heightening structure is raised along the axial direction of the cylinder bore to increase the axial dimension between the cylinder head mounting surface and the cylinder block base.

3. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 2, characterized in that: The height of the integrated heightening structure is 10mm.

4. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The optimized cooling channels are continuously arranged around the four cylinder bores to form a surrounding cooling structure.

5. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 4, characterized in that: The cooling optimization channel forms an upper cooling extension section in the area near the cylinder head mounting surface. The upper cooling extension section is correspondingly provided with the integrated heightening structure, and the extension height of the upper cooling extension section along the cylinder bore axis is consistent with the heightening height of the integrated heightening structure, so that the coolant flow area extends to the upper area of ​​the combustion chamber corresponding to the integrated heightening structure.

6. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The heightened areas of the integrated heightened structure corresponding to the four cylinder bores are set at the same height.

7. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The cylinder block base and the integrated heightened structure are cast from the same cast iron material.

8. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The cylinder base and the integrated heightened structure are integrally cast from molten iron that has undergone segmented constant-temperature melting and inoculation treatment.

9. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The cylinder block base and the integrated heightened structure are integrally formed using a directional flow-controlled casting process.

10. The integrated heightened combustion chamber four-cylinder cast iron racing engine block as described in claim 1, characterized in that: The cylinder block base and the integrated heightened structure are treated with a gradient constant temperature stress relief aging process.

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