Cavity structure core box based on ship four-stroke engine

Abstract

The utility model relates to a cavity structure core box based on a ship four-stroke engine, and belongs to the technical field of ship large-cylinder-diameter medium-speed four-stroke engines. The air inlet valve seat ring and the exhaust valve seat ring are arranged at the bottom of the core box shell, the air valve mechanism penetrates through the core box shell and is matched with the air inlet valve seat ring and the exhaust valve seat ring, and the air inlet channel and the exhaust channel are arranged in the core box shell and are connected with the air inlet valve seat ring and the exhaust valve seat ring respectively. The top of the core box shell and the air valve mechanism are connected with an air valve spring pressing mechanism; a plurality of hollow cavities which are not communicated are formed in the core box shell, the hollow cavities are connected through reinforcing ribs, and preset distances are reserved between the hollow cavities and the air inlet channel and between the hollow cavities and the air outlet channel. By arranging the hollow cavity and the reinforcing rib structure, the weight is effectively reduced, and the structural stability is ensured; an integral processing structure is adopted, so that the assembly complexity is reduced; the air passage test of engines with different cylinder diameters is realized through a principle of similar structure and flow.

Description

Technical Field

[0001] This utility model belongs to the technical field of marine large-bore medium-speed four-stroke engines, and in particular relates to a cavity structure core box based on a marine four-stroke engine. Background Technology

[0002] In the field of traditional marine medium-speed four-stroke engine technology, the structure of its intake and exhaust ports has a decisive influence on the vortex of internal airflow and the distribution of the in-cylinder mixture near top dead center, thus affecting the entire combustion and power stroke of the medium-speed four-stroke engine. Therefore, well-organized gas flow within the intake ports plays a very positive role in optimizing the uniformity of the in-cylinder mixture and promoting flame diffusion combustion.

[0003] To verify the design level of the engine's air passage structure and accurately evaluate the flow capacity of the air passage product, traditional methods typically involve manufacturing an integrated air passage core box based on an air passage design model. This involves machining the air passage, seat ring, valve, and valve seat from a single piece of metal or resin material to simulate the shape of the actual internal air passage area of ​​an engine. This core box is then mounted on an air passage steady-flow test bench, and its flow performance is tested through specialized blowing tests. However, in the field of marine large-bore medium-speed four-stroke engine technology, due to the generally enormous size of engines, continuing to use the traditional integrated air passage core box for testing often results in excessively heavy prototypes. This poses significant difficulties in hoisting, handling, adjusting position, and checking the overall airtightness of the core box during testing. Furthermore, the structural characteristics of the integrated air passage core box itself often significantly increase material costs. Therefore, the traditional integrated structure is not perfectly suitable for the testing of marine medium-speed four-stroke engine air passages. Utility Model Content

[0004] The purpose of this invention is to provide a cavity structure core box based on a marine four-stroke engine, which is specifically suitable for the air passage testing of a marine large-bore medium-speed four-stroke engine.

[0005] To achieve the above objectives, the present invention provides a cavity structure core box based on a marine four-stroke engine, including a core box shell, an intake valve seat and an exhaust valve seat located at the bottom of the core box shell, a valve mechanism passing through the core box shell and cooperating with the intake valve seat and the exhaust valve seat, and an intake passage and an exhaust passage located inside the core box shell and respectively connecting the intake valve seat and the exhaust valve seat; a valve spring clamping mechanism is connected to the top of the core box shell and the valve mechanism; the core box shell has multiple non-connected hollow cavities inside, each hollow cavity is connected by reinforcing ribs, and a preset distance is maintained between the hollow cavities and the intake passage and the exhaust passage.

[0006] Preferably, the hollow cavity is a completely hollow structure, and its number and layout are adapted to the size and weight requirements of the core box shell.

[0007] Preferably, the thickness and distribution of the reinforcing ribs are adapted to the load-bearing requirements of the core box shell, in order to prevent structural deformation caused by the hollow cavity.

[0008] Preferably, the valve mechanism includes a valve guide and a valve; the valve guide is fixed inside the core box housing by an interference fit, the valve passes through the valve guide, one end of which is a flared valve head that is sealed to the intake valve seat or the exhaust valve seat, and the other end is connected to the valve spring clamping mechanism.

[0009] Preferably, the valve spring clamping mechanism includes a locking clip, a valve spring seat, and a valve spring; the valve spring seat is fixed to the top of the valve by the locking clip, and the valve spring is sleeved on the outside of the valve, with its two ends abutting against the valve spring seat and the top of the core box shell, respectively, to press the valve against the intake valve seat or the exhaust valve seat and ensure sealing.

[0010] Preferably, the valve spring is a helical spring, the outer diameter of which matches the inner diameter of the valve spring seat, and the inner diameter of which matches the outer diameter of the valve, so as to achieve stable force transmission.

[0011] Preferably, the bottom of the core box housing is provided with mounting positioning holes for installing the intake valve seat and the exhaust valve seat.

[0012] Preferably, the intake valve seat and the exhaust valve seat are installed in the positioning hole at the bottom of the core box housing by interference fit, and the inner surface is smooth and precisely fits with the valve head of the air valve to form a sealing interface.

[0013] Preferably, both the intake duct and the exhaust duct are curved pipe structures, the shape of which is adapted to the air intake and exhaust flow characteristics of the engine, in order to guide the airflow to generate vortices and reduce flow resistance.

[0014] Preferably, the core box shell is integrally formed by machining or 3D printing, and the exhaust duct, the intake duct, the intake valve seat, the exhaust valve seat and the hollow cavity structure are directly formed in the blank material.

[0015] In summary, this utility model has the following beneficial technical effects:

[0016] This utility model features a core box with multiple hollow cavities, effectively reducing the weight of the core box sample and greatly facilitating testing and hoisting operations. Simultaneously, the uniquely designed reinforcing rib structure provides strong support for the overall frame of the core box, effectively preventing deformation due to its own weight caused by the hollow structure, and ensuring the airtightness and structural stability of the core box.

[0017] This invention adopts an integral processing structure, with integrated printing molding during the manufacturing process, minimizing the complex assembly of unnecessary parts and improving manufacturing convenience. While ensuring that the airflow characteristics of the engine's air passages are not altered, the airtightness of the core box is guaranteed with as few assembly structures as possible.

[0018] This invention belongs to the technical field of marine large-bore medium-speed four-stroke engines and is mainly applied to a steady-flow blowing test bench. By utilizing the principle of structural and flow similarity, the core box shell, intake valve seat, exhaust valve seat, valve mechanism, valve spring clamping mechanism, etc., can be proportionally reduced or enlarged to the existing core box size, enabling steady-flow blowing tests of four-stroke engines with different cylinder diameters. This has broad application prospects and practical value. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the overall structure of the cavity structure core box based on a marine four-stroke engine of this utility model;

[0020] Figure 2 This is a cross-sectional schematic diagram of the air intake passage in the core box of the cavity structure based on a marine four-stroke engine of this utility model.

[0021] Figure 3 This is a cross-sectional schematic diagram of the exhaust passage in the core box of the cavity structure based on a marine four-stroke engine of this utility model.

[0022] Figure 4 This is a schematic diagram of the gas valve mechanism in the core box of the cavity structure based on a marine four-stroke engine according to this utility model.

[0023] Figure 5 This is a schematic diagram of the valve spring clamping mechanism in the core box of the cavity structure of a marine four-stroke engine based on this utility model.

[0024] Reference numerals in the attached drawings: 1. Core box housing; 2. Intake valve seat ring; 3. Exhaust valve seat ring; 4. Hollow cavity; 5. Exhaust passage; 6. Intake passage; 7. Valve mechanism; 8. Valve spring clamping mechanism; 9. Valve guide; 10. Valve; 11. Locking clip; 12. Valve spring seat; 13. Valve spring. Detailed Implementation

[0025] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0026] This utility model discloses a cavity structure core box based on a marine four-stroke engine, specifically suitable for air passage testing of large-bore, medium-speed marine four-stroke engines. Through optimized design, this core box effectively solves many problems related to weight, cost, and manufacturing processes associated with traditional integrated air passage core boxes, while ensuring testing accuracy.

[0027] This invention relates to the air intake structure of a large-bore marine four-stroke engine. The air intake, valve seat, and other components are machined from a single blank material, or manufactured using 3D printing. The core box contains multiple hollow cavities 4, effectively reducing its overall weight. Furthermore, reinforcing ribs are provided between the hollow cavities 4 to prevent deformation due to their weight. Therefore, this hollow cavity 4 structure core box provides excellent airtightness while effectively reducing weight, material costs, and manufacturing cycle.

[0028] This utility model's core box mainly includes a core box shell 1, an intake valve seat ring 2, an exhaust valve seat ring 3, a hollow cavity 4, an exhaust passage 5, an intake passage 6, a valve mechanism 7, and a valve spring clamping mechanism 8. The core box shell 1 serves as the main frame, its shape based on a marine medium-speed four-stroke engine design. It contains multiple hollow cavities 4, which are completely hollow structures and not directly connected to each other, but rather linked by reinforcing ribs to support the shell and prevent deformation due to its own weight. The upper and lower surfaces of the shell are provided with mounting and positioning holes for the valve springs 13, the intake valve seat ring 2, and the exhaust valve seat ring 3, providing mounting bases and positioning holes for these components. This simulates the shape of the engine's air passage area, providing a basic structure for air passage testing. Simultaneously, the hollow cavity design reduces its own weight and material costs.

[0029] Both the intake valve seat 2 and the exhaust valve seat 3 are installed in the positioning holes at the bottom of the core housing 1 via an interference fit, respectively near the side where the intake passage 6 is located and the side where the exhaust passage 5 is located. The intake valve seat 2 has a ring-shaped structure with a smooth inner surface, which fits tightly with the bottom surface of the valve 10 to ensure sealing, provide a sealing interface for the intake process, prevent gas leakage, and ensure intake efficiency. The exhaust valve seat 3 has a similar structure, adjusted according to the design of the bottom of the valve 10, to provide a sealing interface for the exhaust process and ensure exhaust efficiency.

[0030] The intake manifold 6 and exhaust manifold 5 are located inside the core box housing 1, connecting the intake valve seat 2 to the intake inlet of the core box and the exhaust valve seat 3 to the exhaust outlet of the core box, respectively. The intake manifold 6 is a curved pipe structure designed to guide fresh air or air-fuel mixture into the cylinder. Its shape and size are optimized according to the engine's intake flow characteristics to generate good vortex and air-fuel mixture distribution. Simulating the engine's intake manifold 6, it provides a passage for the intake process, optimizes airflow, improves the uniformity of the air-fuel mixture in the cylinder, promotes flame diffusion and combustion, and enhances engine combustion efficiency. The exhaust manifold 5, on the other hand, guides exhaust gas out. It is a curved pipe structure, and its shape and size are optimized according to the engine's exhaust flow characteristics to reduce flow resistance and improve exhaust efficiency. Simulating the engine's exhaust manifold 5, it provides a passage for the exhaust process, ensuring smooth exhaust gas discharge, reducing exhaust back pressure, and improving engine performance.

[0031] The valve mechanism 7 mainly consists of a valve guide 9 and a valve 10, which pass through the core housing 1. The valve guide 9 is a tubular structure with a smooth inner surface through which the valve 10 passes. It is installed with the core housing 1 via an interference fit, providing precise guidance for the valve 10 and ensuring that it can move accurately up and down to achieve a sealing fit with the valve seat, thus guaranteeing the cylinder's sealing performance. The valve 10 is a long rod-shaped structure that passes through the valve guide 9 and extends to the intake valve seat 2 or exhaust valve seat 3. One end is a valve head, used for a sealing fit with the intake valve seat 2 or exhaust valve seat 3, and the other end is connected to the valve spring clamping mechanism 8, controlling the intake and exhaust processes of the cylinder. The opening and closing of the valve 10 realizes the entry and exit of gas, ensuring the normal operating cycle of the engine. The valve head is flared and has a smooth surface. The contact surface with the intake valve seat 2 or exhaust valve seat 3 is precision machined to ensure a good sealing effect.

[0032] The valve spring clamping mechanism 8 is located on the top of the core box housing 1 and is connected to the valve mechanism 7. It mainly includes a locking clip 11, a valve spring seat 12, and a valve spring 13. The locking clip 11 is a ring-shaped or clamping structure used to connect the valve 10 and the valve spring seat 12. The valve spring seat 12 is a disc-shaped or ring-shaped structure with a through hole in the middle. It is fixed to the top of the valve 10 by the locking clip 11 and provides support for the valve spring 13. The valve spring 13 is a helical spring structure with a certain elasticity and strength. It is sleeved on the outside of the top of the valve 10 and installed between the valve spring seat 12 and the top of the core box shell 1. Its outer diameter matches the inner diameter of the valve spring seat 12, and its inner diameter matches the outer diameter of the valve 10 to ensure good installation and force transmission. The valve spring 13 presses the valve head of the valve 10 against the intake valve seat 2 or the exhaust valve seat 3 by the spring force, ensuring that the surface of the valve 10 is in close contact with the surface of the intake valve seat 2 or the exhaust valve seat 3, effectively ensuring the sealing of the core box and preventing gas leakage. At the same time, the valve spring 13 can also absorb the impact force of the valve 10 during operation, protecting the valve 10 and the valve seat from damage.

[0033] The cavity structure core box described in this utility model contains multiple hollow cavities 4 (the hollow cavities 4 must maintain a certain distance from the exhaust duct 5 and the air intake duct 6), which can effectively reduce the weight of the core box sample and greatly facilitate the hoisting operation requirements for testing. At the same time, its uniquely designed reinforcing rib structure can effectively support the overall frame of the core box shell 1, avoiding the problem of self-weight deformation caused by the hollow structure of the core box, and ensuring the airtightness and structural stability of the core box.

[0034] During manufacturing, the core box adopts an integral machining structure. The air passages, valve seats, and other shapes can be machined from a single blank material, or directly manufactured using 3D printing. This minimizes the complex assembly of unnecessary parts, facilitating the manufacturing process, effectively reducing material costs, and shortening the manufacturing cycle. Furthermore, without altering the engine's airflow characteristics, the core box's airtightness is ensured with minimal assembly structures.

[0035] Furthermore, the core box of this invention belongs to the technical field of marine large-bore medium-speed four-stroke engines and is mainly used on a steady-flow blowing test bench. By utilizing the principle of structural and flow similarity, the core box shell 1, intake valve seat 2, exhaust valve seat 3, valve mechanism 7, valve spring clamping mechanism 8, etc., can be proportionally reduced or enlarged to the existing core box size to achieve steady-flow blowing tests for four-stroke engines of different cylinder diameters, demonstrating broad application prospects and practical value.

[0036] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., 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 cavity structure core box based on a marine four-stroke engine, characterized in that, The device includes a core box shell (1), an intake valve seat (2) and an exhaust valve seat (3) located at the bottom of the core box shell (1), a valve mechanism (7) passing through the core box shell (1) and cooperating with the intake valve seat (2) and the exhaust valve seat (3), and an intake passage (6) and an exhaust passage (5) located inside the core box shell (1) and respectively connecting the intake valve seat (2) and the exhaust valve seat (3); a valve spring pressing mechanism (8) is connected to the top of the core box shell (1) and the valve mechanism (7); the core box shell (1) has multiple non-connected hollow cavities (4) inside, which are connected by reinforcing ribs, and a preset distance is maintained between the hollow cavity (4) and the intake passage (6) and the exhaust passage (5).

2. The cavity structure core box based on a marine four-stroke engine according to claim 1, characterized in that, The hollow cavity (4) is a completely hollow structure, and its number and layout are adapted to the size and weight requirements of the core box shell (1).

3. The cavity structure core box based on a marine four-stroke engine according to claim 2, characterized in that, The thickness and distribution of the reinforcing ribs are adapted to the load-bearing requirements of the core box shell (1) to prevent structural deformation caused by the hollow cavity (4).

4. The cavity structure core box based on a marine four-stroke engine according to claim 3, characterized in that, The valve mechanism (7) includes a valve guide (9) and a valve (10); the valve guide (9) is fixed inside the core box housing (1) by an interference fit, and the valve (10) passes through the valve guide (9), one end of which is a flared valve head that is sealed to the intake valve seat (2) or the exhaust valve seat (3), and the other end is connected to the valve spring pressing mechanism (8).

5. The cavity structure core box based on a marine four-stroke engine according to claim 4, characterized in that, The valve spring pressing mechanism (8) includes a locking clip (11), a valve spring seat (12), and a valve spring (13). The valve spring seat (12) is fixed to the top of the valve (10) by the locking clip (11). The valve spring (13) is sleeved on the outside of the valve (10), and its two ends abut against the valve spring seat (12) and the top of the core box shell (1) respectively, for pressing the valve (10) against the intake valve seat (2) or the exhaust valve seat (3) and ensuring sealing.

6. The cavity structure core box based on a marine four-stroke engine according to claim 5, characterized in that, The valve spring (13) is a helical spring, whose outer diameter matches the inner diameter of the valve spring seat (12) and whose inner diameter matches the outer diameter of the valve (10) to achieve the transmission of stable force.

7. The cavity structure core box based on a marine four-stroke engine according to any one of claims 1-6, characterized in that, The bottom of the core box housing (1) is provided with mounting and positioning holes for installing the intake valve seat (2) and the exhaust valve seat (3).

8. The cavity structure core box based on a marine four-stroke engine according to claim 7, characterized in that, The intake valve seat (2) and the exhaust valve seat (3) are installed in the positioning hole at the bottom of the core box shell (1) by interference fit. The inner surface is smooth and is precisely matched with the valve head of the air valve (10) to form a sealing interface.

9. The cavity structure core box based on a marine four-stroke engine according to any one of claims 1-6, characterized in that, Both the intake duct (6) and the exhaust duct (5) are curved pipe structures, whose shapes are adapted to the air intake and exhaust flow characteristics of the engine, and are used to guide the airflow to generate vortices and reduce flow resistance.

10. The cavity structure core box based on a marine four-stroke engine according to any one of claims 1-6, characterized in that, The core box shell (1) is integrally formed by cutting or 3D printing, and the exhaust duct (5), the intake duct (6), the intake valve seat (2), the exhaust valve seat (3) and the hollow cavity (4) are directly formed in the blank material.

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